Comparison of paclitaxel-, 5-fluoro-2'-deoxyuridine-, and epidermal growth factor (EGF)-induced apoptosis. Evidence for EGF-induced anoikis

Epidermal growth factor (EGF), a hormone that stimulates proliferation of many cell types, induces apoptosis in some cell lines that overexpress the EGF receptor. To evaluate the mechanism of EGF-induced apoptosis, MDA-MB-468 breast cancer cells were examined by microscopy, flow cytometry, immunoblotting, enzyme assays, and affinity labeling after treatment with EGF, paclitaxel, or 5-fluoro-2'-deoxyuridine (5FUdR). Apoptosis induced by all three agents was accompanied by activation of caspases-3, -6, and -7, as indicated by disappearance of the corresponding zymogens from immunoblots, cleavage of substrate polypeptides in situ, and detection of active forms of these caspases in cytosol and nuclei using fluorogenic assays and affinity labeling. Further analysis indicated involvement of the cytochrome c/Apaf-1/caspase-9 pathway of caspase activation, but not the Fas/Fas ligand pathway. Interestingly, caspase activation was consistently lower after EGF treatment than after paclitaxel or 5FUdR treatment. Additional experiments revealed that the majority of cells detaching from the substratum after EGF (but not paclitaxel or 5FUdR) were morphologically normal and retained the capacity to readhere, suggesting that EGF-induced apoptosis involves cell detachment followed by anoikis. These observations not only indicate that EGF- and chemotherapy-induced apoptosis in this cell line involve the same downstream pathways but also suggest that detachment-induced apoptosis is responsible for the paradoxical antiproliferative effects of EGF.

Haploinsufficiency of desmoplakin causes a striate subtype of palmoplantar keratoderma

Desmosomes are highly organized intercellular adhesive junctions that are particularly prominent in epidermis and other tissues experiencing mechanical stress. Desmoplakin, a constitutive component of the desmosomal plaque, is the most abundant protein present in such junctions and plays a critical role in linking the intermediate filament network to the plasma membrane in these tissues. Here we report the first mutation in the gene encoding desmoplakin. The identified mutation, resulting in a null allele and haploinsufficiency, was observed in genomic DNA from a kindred with the dominantly inherited skin disorder, striate palmoplantar keratoderma. Affected individuals had a linear pattern of skin thickening on the fingers and palms and circumscribed areas of skin thickening on the soles. Affected skin demonstrated loosening of intercellular connections, disruption of desmosome-keratin intermediate filament interactions and a proportion of rudimentary desmosomal structures. The disorder mapped to chromosome 6p21 with a maximum lod score of 10.67. The mutation was a heterozygous C-->T transition in exon 4 of the desmoplakin gene and predicted a premature termination codon in the N-terminal region of the peptide. This is the first reported mutation of desmo-plakin and also the first inherited skin disorder in which haploinsufficiency of a structural component has been implicated. It identifies dosage of desmoplakin as critical in maintaining epidermal integrity.

A phase II "window" study of topotecan in untreated patients with high risk adult acute lymphoblastic leukemia

To further evaluate the activity of topotecan (TPT) in acute leukemia, TPT was administered (2.1 mg/m2/day for 5 days by continuous i.v. infusion) to adult patients with previously untreated acute lymphoblastic leukemia (ALL) with high-risk features (13 patients) or relapsed ALL (1 patient). Patients achieving a partial response or significant hematological improvement received a second course. All patients subsequently received standard treatment for ALL. Because complete response was achieved in only 1 of 14 patients, the study was terminated prematurely. An additional patient achieved minimal response, and a third patient normalized her hemogram despite ongoing leukemia in the marrow. Overall, six patients had significant hematological improvement (normalization of platelet and/or absolute neutrophil count). Two patients expired due to infections during induction chemotherapy. The primary nonhematological toxicities were mucositis and diarrhea. Exposure to TPT did not appear to influence the response to subsequent standard chemotherapy. The mean steady-state TPT plasma concentration, 16.1+/-1 nM, overlapped the range of LD90 values of primary human leukemia specimens. Cellular topo I content varied over a 3-fold range, encompassing levels found previously in relapsed patients. No relationship was found between topo I expression and markers of cellular proliferation or response to therapy. In contrast, low expression of the apoptosis inhibitor Bcl-2 was associated with response to TPT therapy. TPT has significant, albeit modest, single-agent activity against high-risk adult ALL. This study demonstrates the feasibility of evaluating promising new therapeutic agents in untreated patients with acute leukemia at high risk for failure with conventional therapy.

Evidence for a second genetic locus in Carney complex

Carney complex (MIM no. 160980) is an autosomal dominant condition of lentiginosis, cutaneous and cardiac myxomas and multiple endocrine neoplasia. A locus for Carney complex has recently been mapped to chromosome 2p16. We have studied two Northern Irish families with this disorder. Linkage analysis was performed on the families using five highly informative dinucleotide repeat markers covering this area. Negative logarithm of the odds scores were obtained for all markers at all recombination fractions. We conclude that Carney complex is genetically as well as clinically heterogeneous.

A novel insertional mutation in loricrin in Vohwinkel's Keratoderma

A mutation in the gene encoding loricrin has recently been reported in a subset of patients with Vohwinkel's Keratoderma manifesting an associated ichthyosiform dermatosis. We have studied a further kindred with this clinical phenotype. Microsatellite marker analysis was consistent with linkage to chromosome 1q21 and direct sequencing of loricrin identified a heterozygous mutation with an insertion of a T residue at codon 209. This mutation is predicted to produce a mutant protein with a frameshift of its terminal 107 amino acids and to be 22 amino acids longer than the wild-type protein due to a delayed termination codon. The only previously reported mutation is a G insertion producing a frameshift after codon 231. The novel mutation we report is likely to have a similar functional effect on cornified envelope formation, with disturbance of transglutaminase-mediated cross-linking of envelope components, and serves to confirm the predicted role of insertional mutations in Vohwinkel's Keratoderma associated with ichthyosis.

A primer on continuous renal replacement therapy for critically ill patients

OBJECTIVES

To characterize the multiple continuous renal replacement therapy (CRRT) techniques available for the management of critically ill adults, and to review the indications for and complications of use, principles of drug removal during CRRT, drug dosage individualization guidelines, and the influence of CRRT on patient outcomes.

DATA SOURCES

MEDLINE (January 1981-December 1996) was searched for appropriate publications by using terms such as hemofiltration, ultrafiltration, hemodialysis, hemodiafiltration, medications, and pharmacokinetics; selected articles were cross-referenced.

STUDY SELECTION

References selected were those considered to enhance the reader's knowledge of the principles of CRRT, and to provide adequate therapies on drug disposition.

DATA SYNTHESIS

CRRTs use filtration/convection and in some cases diffusion to treat hemodynamically unstable patients with fluid overload and/or acute renal failure. Recent data suggest that positive outcomes may also be attained in patients with other medical conditions such as septic shock, multiple organ dysfunction syndrome, and hepatic failure. Age, ventilator support, inotropic support, reduced urine volume, and elevated serum bilirubin concentrations have been associated with poor outcomes. Complications associated with CRRT include bleeding due to excessive anticoagulation and line disconnections, fluid and electrolyte imbalance, and filter and venous clotting. CRRT can complicate the medication regimens of patients for whom it is important to maintain drug plasma concentrations within a narrow therapeutic range. Since the physicochemical characteristics of a drug and procedure-specific factors can alter drug removal, a thorough assessment of all factors needs to be considered before dosage regimens are revised. In addition, an algorithm for drug dosing considerations based on drug and CRRT characteristics, as well as standard pharmacokinetic equations, is proposed.

CONCLUSIONS

The use of CRRT has expanded to encompass the treatment of disease states other than just acute renal failure. Since there is great variability among treatment centers, it is premature to conclude that there is enhanced survival in CRRT-treated patients compared with those who received conventional hemodialysis. This primer may help clinicians understand the need to individualize these therapies and to prospectively optimize the pharmacotherapy of their patients receiving CRRT.

Autosomal recessive inheritance of erythrokeratoderma variabilis

Erythrokeratoderma variabilis is a rare genodermatosis conventionally regarded as autosomal dominant in inheritance. We describe the clinical features and light and electron microscopic findings in two affected siblings born to unaffected parents and suggest an autosomal recessive mode of inheritance in this family. We also briefly review the literature on this disorder.

Granulomatous contact dermatitis due to gold earrings

A young female developed persistent nodules at sites of ear piercing with gold earrings and patch testing demonstrated a positive allergic response to gold sodium thiosulphate. Histological examination of the nodules demonstrated a prominent sarcoidal-type granulomatous tissue reaction. This is in contrast to previous reports of lymphocytoma cutis type histology and was associated with the occurrence of epithelioid granulomata at the site of a strongly positive and long-lasting patch-test reaction.

Naevus lipomatosus cutaneous superficialis

A young male presenting with cutaneous papules and plaques in a segmental distribution in the pelvic girdle area is reported. The clinical features were suggestive of naevus lipomatosus cutaneous superficialis, but diagnostic biopsy is essential to demonstrate the typical histopathological features and exclude important differential diagnoses such as segmental neurofibromatosis.

Carney complex: report of a kindred with predominantly cutaneous manifestations

We report a four-generation kindred with the complex of myxomas, spotty pigmentation and endocrine overactivity. This kindred demonstrates a relatively limited phenotypic expression with predominance of cutaneous features. Male-to-male transmission confirms the autosomal dominant nature of the condition. We propose that pilonidal sinus may be an associated manifestation in this kindred.

Altered formation of topotecan-stabilized topoisomerase I-DNA adducts in human leukemia cells

Topotecan (TPT) is a topoisomerase I (topo I) poison that has shown promising antineoplastic activity in solid tumors and acute leukemia. In the present study, a band depletion assay was used to evaluate the ability of TPT to stabilize topo I-DNA adducts in human leukemia cell lines and in clinical leukemia samples ex vivo. This assay showed that 50% of the cellular topo I in HL-60 human myelomonocytic leukemia cells became covalently bound to DNA at an extracellular TPT concentration of 4 micromol/L. In contrast, in 13 clinical specimens of human leukemia harvested before treatment of patients with TPT, the TPT concentration required to stabilize 50% of the cellular topo I in topo I-DNA complexes ranged from 3 to greater than 100 micromol/L (median, 30 micromol/ L). Flow microfluorimetry showed that cellular TPT accumulation varied over only a twofold range and failed to provide evidence for transport-mediated resistance in the clinical samples. These observations raise the possibility that formation of topo I-DNA adducts is diminished in many specimens of refractory/relapsed acute leukemia by a mechanism that might alter topo I sensitivity to TPT.

Contact hypersensitivity in patients with orofacial granulomatosis

BACKGROUND

Orofacial granulomatosis is a clinical entity presenting with chronic swelling of the oral or facial tissues in association with histological evidence of noncaseating granulomatous inflammation. Its cause remains unclear, but a possible role of contact sensitivity to dietary components has been proposed.

OBJECTIVES

This study was performed to document the prevalence of contact sensitivity to food additives in patients with orofacial granulomatosis and assess the role of elimination diets in management.

METHODS

Successive patients with a clinical diagnosis of orofacial granulomatosis were patch tested to the European Standard series and an Oral Battery containing common food additives. In addition, testing for immediate contact reactions to components of the Oral Battery was performed. In selected cases, appropriate elimination diets were implemented.

RESULTS

Forty-eight patients were investigated. Ten showed positive reactions to components of the Oral Battery on standard patch testing and, of these, seven showed improvement on an elimination diet.

CONCLUSIONS

Orofacial granulomatosis is a heterogenous clinical entity. Patch testing permits identification of a subgroup of patients likely to benefit from dietary manipulation and allows more appropriate targeting of such treatment.

Anogenital warts in prepubertal children: pathogenesis, HPV typing and management

The incidence of anogenital warts in prepubertal children is increasing. Modes of transmission of human papillomavirus to the anogenital area include perinatal, autoinoculation and heteroinoculation, sexual abuse and possibly indirect transmission via fomites. It was previously thought that childhood sexual abuse was the most common mode of transmission and human papillomavirus types 6 and 11 were most often detected. More recent studies, however, would suggest that perinatal infection and autoinoculation or heteroinoculation may be much more prevalent than originally thought. It has been increasingly reported that human papillomavirus type 2 is present in a significant proportion of cases. Assessment of children should be multidisciplinary and sexual abuse should be considered in every case. Treatment modalities, although similar to adult disease, are particularly dependent on individual factors. In view of the as yet unknown risk of subsequent anogenital neoplasia it is recommended that individuals should have regular follow-up on a long-term basis.

Phase I trial and pharmacologic trial of sequences of paclitaxel and topotecan in previously treated ovarian epithelial malignancies: a Gynecologic Oncology Group study

PURPOSE

A phase I and pharmacologic study to evaluate the feasibility of administering paclitaxel (PTX) in combination with topotecan (TPT) without and with granulocyte colony-stimulating factor (G-CSF) in women with recurrent or refractory ovarian cancer.

PATIENTS AND METHODS

TPT was administered as a 30-minute infusion daily for 5 days and PTX was given as a 24-hour infusion (PTX-24) either before TPT on day 1 or after TPT on day 5. Each patient received both schedules on an alternating basis every 3 weeks. Sequential dose escalation of TPT or PTX-24 without and with G-CSF resulted in five dosage permutations of TPT/PTX (mg/ m2): 0.75/135 without G-CSF and 0.75/135, 1.25/135, 1.50/135, and 1.25/170 with G-CSF.

RESULTS

Twenty-two patients received 109 courses of therapy. Dose-limiting myelosuppression consistently occurred at the first TPT/PTX-24 dose level (0.75/135 mg/m2) in the absence of G-CSF support. Although the addition of G-CSF resulted in reduced rates of complicated neutropenia, the incidences of dose-limiting neutropenia and thrombocytopenia were unacceptably high after the doses of either TPT or PTX-24 were increased. Paired analysis showed similar hematologic toxicities between the two sequences of drug administration. The pharmacologic behavior of both TPT and PTX-24 was not altered by drug sequencing. Major antitumor responses occurred in 40% of patients with measurable and assessable disease, including 45% and 9% of patients with potentially cisplatin-sensitive and -resistant tumors, respectively.

CONCLUSION

The recommended doses of TPT on a daily times-five schedule combined with PTX-24 in these patients were 0.75 mg/m2/d and 135 mg/m2, respectively, with G-CSF support. Although this dose of PTX has significant single-agent activity in ovarian cancer, the dose of TPT is much lower than the TPT dose at which single-agent activity has been observed. Due to the inability to administer near relevant single-agent doses of both drugs in combination, as well as the requirement for G-CSF support, further evaluations of this regimen in women with refractory or recurrent ovarian cancer are necessary before it can be recommended for previously treated patients in this setting.

Congenital triangular alopecia

We report a child with bilateral congenital triangular alopecia. Shaving the scalp and inserting intravenous cannulas into scalp vessels during the neonatal period was misconstrued by the parents as the cause of hair loss, and resulted in medicolegal implications.

Combined therapy trial with interferon alpha-2a and ablative therapy in the treatment of anogenital warts

OBJECTIVE

To determine whether the combination of systemically administered interferon alpha-2a and ablative surgery for the treatment of genital and/or perianal warts produces a 30% or greater improvement in lasting response rate compared with a control group receiving a combination of placebo and ablative therapy.

DESIGN

Randomised, triple-blind, placebo-controlled trial using 1 or 3 MIU of interferon alpha-2a or placebo administered subcutaneously three times weekly for 10 weeks in combination with ablative surgery.

SETTING

International, multicentre study in 10 genitourinary medicine clinics.

PATIENTS

Two hundred and fifty patients with anogenital warts.

MAIN OUTCOME MEASURES

Lasting response at week 38.

RESULTS

Standard efficacy analysis at week 38 showed a lasting response in 51% (35/68) of 3 MIU interferon-treated patients, 48% (30/63) of 1 MIU interferon-treated patients and 43% (29/67) of placebo-treated patients.

CONCLUSIONS

With the doses and regime described, treatment with interferon alpha-2a in combination with ablative therapy is not significantly superior in the treatment of anogenital warts than placebo and ablative therapy.

Programmed cell death in human breast cancer cells

The need for improved systemic therapy for breast cancer is great. Cancer growth represents an imbalance between cell proliferation and cell death: thus, effective anti-cancer therapies may act to decrease cell proliferation or increase cell death, or both. This chapter delineates the role of the programmed cell death process in maintaining homeostasis in normal mammary tissues. The preservation of such death pathways in malignant mammary cells and the ability of chemotherapeutic agents to initiate the programmed cell death process in these cells is reviewed. Finally, ongoing research exploring new ways to take advantage of these death pathways in the clinical setting is examined.

Multiple dermatofibromas in a patient with HIV infection

We report the case of a 26-year-old man with haemophilia B and human immunodeficiency virus infection (HIV) who presented with a short history of multiple dermatofibromas. He also had troublesome psoriasis for which he was receiving acitretin with UVB therapy and had recently discontinued low-dose daily prednisolone for associated arthropathy. Multiple dermatofibromas are rare and have been reported previously in association with autoimmune disease, especially in individuals receiving immunosuppressive therapy. We believe this to be the first report of multiple dermatofibromas in an individual with advanced HIV infection and propose that it may be related to his viral-mediated immunodeficiency, possibly augmented by UVB and systemic corticosteroid therapy.

Phase I and pharmacologic study of the alkylating agent modulator novobiocin in combination with high-dose chemotherapy for the treatment of metastatic breast cancer

PURPOSE

Resistance to alkylators may potentially be overcome by drugs that inhibits DNA repair, thus improving the efficacy of high-dose chemotherapy. This trial was performed to determine if novobiocin, an agent that inhibits DNA repair, could be given with high-dose alkylators. Study aims were to define the toxicities and maximal-tolerated dose (MTD) of novobiocin and the pharmacokinetics of novobiocin and high-dose cyclophosphamide and thiotepa.

PATIENTS AND METHODS

Thirty-eight women with responsive metastatic breast cancer received high-dose cyclophosphamide (3 to 6 g/m2 over 4 days), thiotepa (400 to 800 mg/m2), and novobiocin (0.5 to 5.0 g/d x 7, orally) with autologous marrow support. Toxicity was monitored. The pharmacology of novobiocin, cyclophosphamide, and thiotepa was evaluated.

RESULTS

There were no toxic deaths. The MTD of novobiocin was 4 g/d. All seven patients treated at 5 g/d developed grade III/IV mucositis and vomiting. The severity of mucositis correlated with the plasma levels of novobiocin. Other severe toxicities were not observed. Plasma novobiocin levels > or = 100 micrograms/mL, which are associated with reversal of drug resistance in animal models, were consistently seen at dose levels greater than 2 g. The dispositions of cyclophosphamide and thiotepa were not altered by novobiocin.

CONCLUSION

Novobiocin may be given with high-dose alkylators in doses that produce plasma levels that augment the activity of these cytotoxics in experimental models. The pharmacology of high-dose cyclophosphamide and thiotepa is unaffected. Novobiocin 4 g/d orally for 7 days is recommended for future study.

A survey of the use of prostitutes (commercial sex workers) by new male attenders at a genito urinary medicine clinic

This study documents the use of prostitutes (commercial sex workers) by new male patients attending a genito urinary medicine clinic. 541 consecutive male patients completed an anonymous self-administered questionnaire. 48 (8.9%) gave a history of previous purchase of sexual services in Northern Ireland and/or elsewhere; 69% of these encounters occurred outside Northern Ireland. The largest group were single men aged 20-29 years. 87% of those who purchased services in Northern Ireland were asked by the prostitute to use a condom compared with 60% elsewhere, but there was no significant difference in actual condom use between both groups (66.7% vs 72.7%) Only 21% of patients who had purchased the services more than once used condoms consistently and 29% were willing to pay more for unprotected sexual intercourse. 40% attributed their attendance at this clinic directly or indirectly to their encounter with a prostitute. Encounters with prostitutes were often related to alcohol consumption, 88% sometimes or always purchasing these services after drinking alcohol. Despite widespread publicity at-risk behaviour involving unprotected sexual intercourse with prostitutes is not uncommon. Health education should be targeted at the young single male who travels outside Northern Ireland.

A randomised, double-blind, parallel group study to compare subcutaneous interferon alpha-2a plus podophyllin with placebo plus podophyllin in the treatment of primary condylomata acuminata

OBJECTIVES

The primary objective was to determine if six weeks treatment with subcutaneous interferon alpha-2a (IFN) and podophyllin 25% W/V administered twice per week, preceded by IFN alpha-2a three times weekly for one week showed a greater complete response rate in patients with primary condylomata acuminata when assessed at week 10 than treatment with podophyllin and placebo injections in the same schedule. The secondary objective was to compare recurrence rates in complete responders at six months in the two treatment groups.

DESIGN

Randomised, double-blind parallel group study.

SETTING

Multicentre study in six genitourinary clinics within the U.K.

PATIENTS

One hundred and twenty-four patients with primary anogenital warts.

MAIN OUTCOME MEASURES

Complete response rate at week 10, and recurrence rate at week 26 in complete responders.

RESULTS

At week 10 analysis of the efficacy population showed complete response in 36% (15/42 patients) of IFN-treated group and 26% (11/43 patients) in the placebo group (no significant difference). Analysis of the safety population at week 26 showed persistence of the complete response in 57% (8/14 patients) of the IFN-treated group and 80% (12/15 patients) of the placebo group (no significant difference). Adverse effects were more common in IFN-treated patients, involved particularly application site reaction and malaise but were generally mild.

CONCLUSIONS

At the dose and with the regime described treatment with IFN alpha-2a in combination with podophyllin is no more effective in the treatment of primary anogenital warts than podophyllin alone and is associated with more adverse events.

Interleukin-3 and bryostatin-1 mediate hyperphosphorylation of BCL2 alpha in association with suppression of apoptosis

Using murine myeloid factor-dependent FDC-P1/ER cells, we demonstrate that the hematopoietic growth factors interleukin-3 and erythropoietin and bryostatin-1, a macrocyclic lactone natural product and potent activator of protein kinase C (PKC), suppress apoptosis and induce the rapid serine phosphorylation of Bc12 alpha. Expression of recombinant wild type Bc12 alpha in NFS/N1.H-7 cells confirms that murine Bc12 alpha is phosphorylated following PKC activation. The PKC inhibitors H-7 and staurosporine, but not the protein kinase A inhibitor HA1004, block not only interleukin-3- and bryostatin-1-induced hyperphosphorylation of Bc12 alpha but also their anti-apoptotic effect on growth factor-dependent cells, suggesting a role for activated PKC in both processes. A potential direct role for a classic isoform of PKC is indicated by the Ca(2+)-dependent nature of phosphorylation of Bc12 alpha mediated by purified PKC in vitro. Comparative phosphopeptide maps confirm that Bc12 alpha phosphorylation occurs on identical serine site(s) whether phosphorylation occurs in cells following agonist treatment or directly by PKC in vitro. These findings strongly support a role for activated PKC in growth factor-induced Bc12 alpha phosphorylation as well as suppression of apoptosis.

Epidermal growth factor-mediated apoptosis of MDA-MB-468 human breast cancer cells

MDA-MB-468 human breast cancer cells lack estrogen receptors, overexpress epidermal growth factor (EGF) receptors, and are growth inhibited by EGF. We show that treatment of MDA-MB-468 cells with EGF leads to inhibition of cell proliferation, fragmentation of DNA into nucleosomal oligomers, and the development of apoptotic morphology. This treatment is associated with increased expression of c-myc, c-fos, jun family members, and transforming growth factor beta 1 mRNA and with partial proteolytic cleavage of poly(ADP-ribose) polymerase and lamin B. The observation that EGF can mediate apoptosis in EGF receptor-overexpressing cells has important implications for clinical efforts directed at the EGF receptor.

Reasons for patient drop-out from an intracavernous auto-injection programme for erectile dysfunction

OBJECTIVE

To identify factors that contribute to patient drop-out rates from an intracavernous auto-injection programme for erectile dysfunction.

PATIENTS AND METHODS

Forty-seven patients who had been successfully treated with intracavernous vasoactive agents but who subsequently failed to attend follow-up appointments were included in the study. Each patient completed a self-administered questionnaire.

RESULTS

Thirty (64%) completed questionnaires were returned. The reasons for withdrawal from treatment are outlined.

CONCLUSIONS

The majority of patients who discontinued intracavernous therapy did so for reasons unrelated to treatment associated problems.

Prostaglandin E1 in the medical management of erectile dysfunction in a genito-urinary medicine clinic

Fifty consecutive patients with erectile failure who had previously proved refractory to papaverine and phentolamine intracavernosal therapy or were inappropriate candidates for such treatment were treated with intracavernosal prostaglandin E1. Forty patients (80%) achieved an erection sufficient for sexual intercourse and after a mean follow-up period of 5.9 months, 32 patients were continuing to use treatment successfully. The average dose was 14 micrograms (range 2.5 to 30 micrograms). There were no cases of priapism or cavernosal fibrosis and no systemic side effects. A low incidence (8%) of local discomfort was reported. We conclude that prostaglandin is a safe and effective vasoactive agent for the treatment of erectile failure in a genito-urinary outpatient clinic.

Pharmacoeconomic issues of sedation, analgesia, and neuromuscular blockade in critical care

Neuromuscular blocking agents (NMBAs) are commonly prescribed as adjunct therapy for many critically ill patients. Controversy exists regarding the appropriate long-term use of these agents, particularly since there are severe potential clinical consequences. The expanded use of NMBAs has had a significant effect on the cost of ICU care. One should determine whether or not NMBAs are being used as adjunct therapy, or as a replacement for optimal sedation and/or analgesia. This article reviews some of the indicative economic issues surrounding the use of sedatives, analgesics, and NMBAs in the critical care arena. Understanding the pharmacokinetic and pharmacodynamic differences of these agents can aid in drug selection and route of administration. Appropriate drug selection can influence the pharmacoeconomics of these agents in the ICU.

Sixteen week dose intense chemotherapy for inoperable, locally advanced breast cancer

Up to 15% of women with breast cancer have locally advanced disease at diagnosis. The poor response of these patients to local therapy alone and the frequent development of disseminated disease suggest that early intensive systemic therapy may benefit these women. Twenty-four patients with non-metastatic, locally advanced, primarily inflammatory, inoperable breast cancer were treated with a 16-week dose-intense chemotherapy regimen as induction therapy. Treatment consisted of 8 repetitive 2-week cycles consisting of 100 mg/m2 cyclophosphamide orally D1-7, 40 mg/m2 doxorubicin intravenously (IV) D1, 1 mg vincristine IV D1, 100 mg/m2 methotrexate IV D1, 10 mg/m2 leucovorin every 6 hours for six oral doses D2-3, and 600 mg/m2 5-FU IV over 2 hours D2. A continuous infusion of 300 mg/m2 5-FU per day was given IV D8-9 of each 2-week cycle. After induction all patients had at least a partial clinical response and were operable; 9/24 (37%) achieved a clinical complete response. All patients underwent at least a simple mastectomy. Pathologic examination revealed no evidence of gross macroscopic tumor in 11/24 patients (46%) and no evidence of microscopic disease in 4/24 patients (17%). Seven of 24 patients (29%) had no microscopic disease in the breast. At a median follow-up of 45 months, there have been 10 relapses in the 24 patients treated with this induction regimen. The actuarial relapse-free survival at 5 years is 58%. Actuarial overall survival at 5 years is 75%. We conclude that this regimen is safe and well-tolerated and that the results of this therapy are sufficiently promising to warrant further study of this regimen in patients with locally advanced breast cancer.

Intracavernosal papaverine and phentolamine for the medical management of erectile dysfunction in a genitourinary clinic

A total of 160 men with erectile failure received treatment with 13,030 intracavernosal papaverine and phentolamine injections as outpatients. One-hundred-and-fifteen (72%) achieved an erection sufficient for sexual intercourse and after a mean follow-up period of 14.1 months, 55 (48%) are still attending and successfully using intracavernous therapy. Sixteen patients had a total of 22 episodes of priapism and one patient developed corporeal fibrosis. We conclude that intracavernous papaverine and phentolamine is an effective therapy for erectile failure in a genitourinary clinic.

Vancomycin and tobramycin clearance in an infant during continuous hemofiltration

OBJECTIVE

To report a case of vancomycin and tobramycin clearance by continuous veno-venous hemofiltration in an infant. Hemofiltration clearance (ClHF) was calculated by two methods and compared for ease and reliability.

METHODOLOGY

Case report of a hospitalized four-month-old infant. With method A, ClHF calculation for vancomycin and tobramycin was determined by accurate collection of ultrafiltrate in five 24-hour periods and a midpoint serum sample. With method B, ClHF calculation was determined by obtaining prefilter sample, postfilter sample, and blood flow through filter (Fick principle) over three study periods, correlating to three of five study periods in method A.

RESULTS

The infant received continuous veno-venous hemofiltration. With method A, vancomycin ClHF ranged from 0.27 to 0.80 mL/min; tobramycin ClHF ranged from 0.32 to 0.91 mL/min. With method B, ClHF for vancomycin ranged from 0 to 2.08 mL/min. Tobramycin ClHF ranged from 0 to 1.6 mL/min when calculated with method B.

CONCLUSIONS

Continuous veno-venous hemofiltration increased the clearance of vancomycin and tobramycin requiring dosage modifications. It appears that method A, which uses the ultrafiltration concentration compared with the serum concentration is more accurate than method B, as it averages fluctuations in ultrafiltrate flow rates. Method B compares a single pre- to postfilter drug concentration and relies on an accurate measurement of ultrafiltration flow rate. Determining ClHF based upon one point in time may overestimate ClHF when the ultrafiltration flow rate varies, as it does in the critically ill. Daily serum concentrations for vancomycin and tobramycin are recommended during continuous veno-venous hemofiltration.

Programmed cell death in an estrogen-independent human breast cancer cell line, MDA-MB-468

Previous studies have demonstrated that estrogen-responsive human breast cancer cells can be induced to undergo an energy-dependent, genetically programmed series of biochemical changes that result in the active suicide of the cells following estrogen ablation. In contrast, estrogen-independent human breast cancer cells do not activate this programmed cell death pathway following estrogen ablation. This could be due either to the absence of the cellular machinery required for programmed cell death or simply to the inability of estrogen ablation to activate this machinery. To discriminate between these two possibilities, the MDA-MB-468 estrogen-independent human mammary adenocarcinoma cell line was used as a model system to study the mechanism of cell death following cytotoxic drug treatment. Exposure of these cells to the fluorinated pyrimidines, 5-fluoro-2'-deoxyuridine or trifluorothymidine, resulted in growth inhibition and loss of proliferative capacity within 24 h. These changes occurred while cell membrane integrity was intact as measured by either cellular morphology or trypan blue exclusion. After 48 h of drug treatment, loss of cell membrane integrity was followed by cell lysis and a rapid decline in cell number. The addition of 16 microM thymidine prior to drug treatment prevented cell death, but thymidine did not rescue these cells once drug treatment was initiated. Analysis of DNA revealed the characteristic fragmentation into nucleosomal oligomers that is a hallmark of programmed cell death. Associated with this death pathway was a 15-fold induction of transforming growth factor beta 1 gene expression that has been previously observed in a variety of cellular systems undergoing programmed cell death. These results indicate that MDA-MB-468 estrogen-independent human mammary carcinoma cells retain the ability to undergo programmed cell death after treatment with cytotoxic drugs that induce a "thymineless" state.

Hepsulfam sensitivity in human breast cancer cell lines: the role of glutathione and glutathione S-transferase in resistance

Hepsulfam (NSC 329680, 1,7-heptanediol disulfamate) is an alkylating agent that showed excellent activity against mouse and human mammary carcinoma in preclinical studies. We therefore studied the cytotoxicity of this drug in six human breast cancer cell lines (AdrRMCF7, WTMCF7, Hs578T, MDA-MB-231, T47D, and MDA-MB-468). Clonogenic assays of these cell lines showed a range of sensitivity with the 90% inhibitory concentration ranging from 3.1 microM hepsulfam (MDA-MB-468) to 32.3 microM hepsulfam (AdrRMCF7) after 24-h exposure to the drug. To evaluate possible mechanisms responsible for this observed variation in sensitivity to hepsulfam, we have studied glutathione S-transferase (GST) activity and glutathione (GSH) in these cell lines. Total cytoplasmic GST activity correlated with sensitivity; the most sensitive cell lines had the lowest GST activity, while the two most resistant cell lines, AdrRMCF7 and Hs578T, had the highest GST levels of the six cell lines. Western blot analysis showed that the only detectable isoenzyme was GST-pi. The amount of GST-pi isoform correlated with hepsulfam sensitivity in the three most resistant cell lines and was undetectable in the three most sensitive cell lines. Cellular concentrations of GSH did not correlate with hepsulfam sensitivity. However, GSH depletion with buthionine sulfoximine increased sensitivity to hepsulfam in a dose-dependent fashion in all six cell lines. Evaluation by mass spectrometry revealed that glutathione can form conjugates with hepsulfam. We conclude that the GST/GSH detoxication system plays a role in the sensitivity of these breast cancer cell lines to hepsulfam.

Sodium hyaluronate as a carrier for intravitreal gentamicin. An experimental study

Fifty mcg of gentamicin was combined with saline or with 0.8% sodium hyaluronate and injected into the vitreous cavity of rabbit eyes with moderate to severe Staphylococcus aureus endophthalmitis. Endophthalmitis was controlled in 9 of 10 eyes. There was no evidence of toxicity with either treatment regimen. Although the clearance study demonstrated statistical differences at all time points studied, the half-lives of both treatment regimens were similar (3.3 h for aqueous gentamicin and 3.6 h for sodium hyaluronate/gentamicin). These results suggest that the vitreous played a role in keeping the aqueous gentamicin in the eye for a longer time, as similar half-lives were shown with both types of treatment. Thus, if a vitrectomy has to be done for the treatment of endophthalmitis, as much as possible of the vitreous should be left in situ to maintain the drug for longer periods in the eye. Also, if it is necessary to remove all vitreous during vitrectomy, it may be more effective to administer the drug with sodium hyaluronate so as to prolong its action inside the eye.

In vitro and in vivo studies with sodium hyaluronate as a carrier for intraocular gentamicin

We compared the in vitro growth of common intraocular pathogens Staphylococcus aureus, Staphylococcus epidermidis and Pseudomonas aeruginosa in rabbit vitreous and in sodium hyaluronate (SH) with and without gentamicin. The minimal inhibitory concentration for gentamicin/SH was 0.5, 0.062 and 2.0 mcg/ml for these pathogens, respectively. After posterior capsulotomy, P. aeruginosa was inoculated into the anterior vitreous and all 15 untreated eyes developed endophthalmitis. In a similar group, aqueous gentamicin administered in the anterior chamber reduced the incidence of endophthalmitis to 10 of 15 eyes. Under similar circumstances, the SH/gentamicin combination lowered the incidence of endophthalmitis significantly to 4 of 15 eyes. The half-life of aqueous gentamicin was 0.9 h, which was shorter than the 2.2 h for SH/gentamicin combination. These results suggest that SH may be a useful carrier for intraocular drug therapy.

Taxol: a unique antineoplastic agent with significant activity in advanced ovarian epithelial neoplasms

STUDY OBJECTIVE

To assess the activity of taxol in patients with advanced, progressive, and drug-refractory ovarian cancer and to delineate more clearly the toxicity of taxol in this patient population.

DESIGN

Nonrandomized, prospective phase II trial.

PATIENTS

Forty-seven patients with drug-refractory epithelial ovarian cancer who had one or more lesions measurable in perpendicular diameters. Of these patients, 45 were evaluable for toxicity and 40 were evaluable for response.

INTERVENTIONS

PATIENTS were treated every 22 days with varying doses of taxol (110 to 250 mg/m2 body surface) given as a 24-hour infusion with subsequent doses based on adverse effects. A premedication regimen was used to avoid acute hypersensitivity reactions.

MEASUREMENTS AND MAIN RESULTS

Twelve patients (30%; CI, 16% to 44%) responded to taxol for periods lasting from 3 to 15 months. The dose-limiting toxicity was myelosuppression with leukocytes affected more severely and commonly than thrombocytes or reticulocytes. Leukopenia was usually brief in duration but was associated with sepsis in 3 cases (2 fatal). Other adverse effects included myalgias, arthralgias, alopecia, diarrhea, nausea, vomiting, mucositis, and peripheral neuropathy. Rare cases of cardiac and central neurotoxicity were also noted.

CONCLUSIONS

Taxol is an active agent in drug-refractory ovarian cancer and deserves further study in combination with other active drugs in previously untreated patients with advanced ovarian cancer.

Pharmacoeconomic impact of critically ill surgical patients

Financial information on 131 patients and drug-related information on 176 patients admitted to a surgical intensive care unit (ICU) were prospectively collected. The average stay was nearly five days and patients received 8.6 drugs per day for a total average exposure of 12.2 different drugs. Antibiotics and analgesics were used in over 90 percent of patients. The patients' diagnoses fit into 53 different diagnosis-related groups (DRG). Hospital costs were significantly greater than DRG payment for an average revenue loss of $17,803 per patient. Patients with a primary diagnosis of sepsis had the largest revenue loss, averaging $54,738. One hundred patients were revenue losers. Total hospital stay was statistically longer than DRG-projected length of stay. Pharmacy charges averaged 13.6 percent of total hospital charges. Patients receiving systemic antifungals, triple antibiotics, catecholamines, and total parenteral nutrition had high hospital and pharmacy costs. This study suggests that ICU patients are costly to hospitals and that drug use is expensive. We suggest that increased pharmacy involvement in the care of ICU patients may help curtail escalating drug costs in these patients.

Clinical response and total and unbound plasma concentrations after lidocaine overdose

Plasma and unbound concentrations and hemodynamic and CNS effects were monitored in a patient after overdose of 2 g of lidocaine HCl infused during 1 h. Hypotension, decreased heart rate, tremors, and nonresponsiveness to stimuli were observed at plasma and unbound concentrations of 17.7 and 12.0 micrograms/ml. The half-lives of decline of plasma and unbound concentrations were 3.8 and 2.7 h; the difference in half-lives was due to nonlinear plasma protein binding.

Hemodialysis of amikacin in critically ill patients

The clearance of amikacin during hemodialysis (HD) was determined in eight critically ill patients. The dialysis period averaged 3.4 h with a blood flow of 200 ml/min. The average amikacin clearance between dialysis was 7.30 +/- 4.78 (SD) ml/min which increased to 37.5 +/- 8.01 ml/min during dialysis. The average serum amikacin concentration before dialysis fell 27% after dialysis. The fraction of drug in the body removed only from dialysis averaged 21%. Although amikacin was cleared more effectively during HD compared to the interdialysis period, the small amount of drug removed suggests that routine supplemental dosing of amikacin after HD may not be necessary.