Lipoteichoic acid stimulates the proliferation, migration and cytokine production of adult dental pulp stem cells without affecting osteogenic differentiation.

AIM: To model in vitro the contact between adult dental pulp stem cells (DPSCs) and lipoteichoic acid (LTA), a cell wall component expressed at the surface of most Gram-positive bacteria. METHODOLOGY: Human DPSCs obtained from impacted third molars were cultured and exposed to various concentrations of S. aureus LTA (0.1, 1.0 and 10 µg mL-1 ). The effects of LTA on DPSCs proliferation and apoptosis were investigated by MTT assay and flow cytometry. Mineralization of DPSCs was evaluated by alizarin red staining assay. Migration was investigated by microphotographs of wound-healing and Transwell migration assays. Reverse transcription polymerase chain reaction was used to examine the effects of LTA on p65 NF-κB translocation and TLR1, TLR2 or TLR6 regulation. Enzyme-linked immunosorbent assay was used to investigate LTA-stimulated DPSCs cytokine production. One-way or two-way ANOVA and Tukey post hoc multiple comparison were used for statistical analysis. RESULTS: DPSCs expressed TLR1, TLR2 and TLR6 involved in the recognition of various forms of LTA or lipoproteins. Exposure to LTA did not up- or down-regulate the mRNAs of TLR1, TLR2 or TLR6 whilst LPS acted as a potent inducer of them [TLR1 (P ≤ 0.05), TLR2 (P ≤ 0.001) and TLR6 (P ≤ 0.001)]. Translocation of p65 NF-κB to the nucleus was detected in LTA-stimulated cells, but to a lesser extent than LPS-stimulated DPSCs (P ≤ 0.001). The viability of cells exposed to LTA was greater than unstimulated cells, which was attributed to an increased proliferation and not to less cell death [LTA 1 µg mL-1 (P ≤ 0.001) and 10 µg mL-1 (P ≤ 0.01)]. For specific doses of LTA (1.0 µg mL-1 ), adhesion of DPSCs to collagen matrix was disturbed (P ≤ 0.05) and cells enhanced their horizontal mobility (P ≤ 0.001). LTA-stimulated DPSCs released IL-6 and IL-8 in a dose-dependent manner (P ≤ 0.0001). At all concentrations investigated, LTA did not influence osteogenic/odontoblastic differentiation. CONCLUSIONS: Human DPSCs were able to sense the wall components of Gram-positive bacteria likely through TLR2 signalling. Consequently, cells modestly proliferated, increased their migratory behaviour and contributed significantly to the local inflammatory response through cytokine release.

Increased serum levels of high-mobility group box 1 (HMGB1) in primary Sjögren's syndrome.

OBJECTIVE: To determine serum levels of high-mobility group box 1 (HMGB1) in patients with primary Sjögren's syndrome (pSS) as compared to healthy volunteers and patients with sicca symptoms, and to determine whether serum HMGB1 levels are correlated with disease activity in pSS. METHODS: Serum HMGB1 levels were determined by enzyme-linked immunosorbent assay (ELISA) in 101 patients with pSS, 13 patients with sicca symptoms, and 40 healthy volunteers. Clinical and laboratory variables were also analysed and serum HMGB1 levels were correlated with the Sjögren's Syndrome Disease Activity Index (SSDAI). RESULTS: The serum levels of HMGB1 were significantly increased in pSS patients as compared to patients with sicca symptoms and healthy controls (p = 0.04 and p = 0.01, respectively). In the subgroups of patients with anti-SSA autoantibodies, the serum levels of HMGB1 were significantly higher than those in the subgroup of pSS patients who were anti-SSA negative and in healthy controls and patients with sicca symptoms (p < 0.001, p < 0.001, and p = 0.004, respectively). There was no significant correlation between serum HMGB1 levels (in pSS patients with anti-SSA autoantibodies) and SSDAI score (r = 0.03, p = 0.83). Patients with active disease had higher HMGB1 levels than patients with low disease activity (p = 0.04), but HMGB1 levels did not correlate with the SSDAI. CONCLUSION: Serum HMGB1 levels are increased in pSS patients and more specifically in patients with SSA autoantibodies. There was, however, no correlation of HMGB1 with the SSDAI.

Link between inflammation and aquaporin-5 distribution in submandibular gland in Sjögren's syndrome?

OBJECTIVE: To determine whether a link exists between inflammation and aquaporin-5 distribution in submandibular glands from three animal models for Sjögren's syndrome: IQI/JIC, r1ΔT/r2n and non-obese diabetic mice. METHODS: Mice of different ages were used. Inflammatory infiltrates were quantified using the focus score. Acinar aquaporin-5 subcellular distribution was determined by immunohistochemistry and quantified using labelling indices. RESULTS: Minor inflammatory infiltrates were present in r1f/r2n mice. Massive inflammatory infiltrates and acinar destruction were observed in 24-week-old non-obese diabetic mice, 10-and 13-month-old IQI/JIC mice and some r1ΔT/r2n mice. Aquaporin-5 immunoreactivity was primarily apical in submandibular glands from 8- and 24-week-old Balb/C mice, 8-week-old non-obese diabetic mice, 2-, 4- and 7-month-old IQI/JIC mice and r1f/r2n mice. In contrast, decreased apical aquaporin-5 labelling index with concomitant increased apical-basolateral, apical-cytoplasmic and/or apical-basolateral-cytoplasmic aquaporin-5 labelling indices was observed in 24-week-old non-obese diabetic, 10- and 13-month-old IQI/JIC and r1ΔT/r2n mice with a focus score≥1. CONCLUSIONS: Altered aquaporin-5 distribution in submandibular acinar cells from IQI/JIC, non-obese diabetic and r1ΔT/r2n mice with a focus score≥1 appears to be concomitant to the presence of inflammatory infiltrates and acinar destruction.

Brain and spinal cord affected by amyotrophic lateral sclerosis induce differential growth factors expression in rat mesenchymal and neural stem cells.

UNLABELLED: Stem cell research raises hopes for incurable neurodegenerative diseases. In amyotrophic lateral sclerosis (ALS), affecting the motoneurones of the central nervous system (CNS), stem cell-based therapy aims to replace dying host motoneurones by transplantation of cells in disease-affected regions. Moreover, transplanted stem cells can serve as a source of trophic factors providing neuroprotection, slowing down neuronal degeneration and disease progression. AIM: To determine the profile of seven trophic factors expressed by mesenchymal stem cells (MSC) and neural stem cells (NSC) upon stimulation with CNS protein extracts from SOD1-linked ALS rat model. METHODS: Culture of rat MSC, NSC and fibroblasts were incubated with brain and spinal cord extracts from SOD1(G93A) transgenic rats and mRNA expression of seven growth factors was measured by quantitative PCR. RESULTS: MSC, NSC and fibroblasts exhibited different expression patterns. Nerve growth factor and brain-derived neurotropic factor were significantly upregulated in both NSC and MSC cultures upon stimulation with SOD1(G93A) CNS extracts. Fibroblast growth factor 2, insulin-like growth factor and glial-derived neurotropic factor were upregulated in NSC, while the same factors were downregulated in MSC. Vascular endothelial growth factor A upregulation was restricted to MSC and fibroblasts. Surprisingly, SOD1(G93A) spinal cord, but not the brain extract, upregulated brain-derived neurotropic factor in MSC and glial-derived neurotropic factor in NSC. CONCLUSIONS: These results suggest that inherent characteristics of different stem cell populations define their healing potential and raise the concept of ALS environment in stem cell transplantation.

Is the T-ligament a ligament? A histological study in equine cadaver forelimbs.

Foot pain is a frequent cause of lameness in horses and can involve multiple structures within the hoof. The T-ligament (an anatomical structure connecting the synovium of the distal interphalangeal joint, the digital flexor tendon sheath and the navicular bursa) is poorly described. Five pairs of equine cadaver distal forelimbs were collected from a slaughterhouse. Sagittal sections (medial, middle and lateral) were obtained and processed with Haematoxylin Eosin Safran, Unna's Orcein, and Picrosirius red stains. Histological assessment revealed that the T-ligament was covered by the surrounding synovia of the distal interphalangeal joint, the digital flexor tendon sheath and the navicular bursa. Its collagen content was lower (30.01%±10.15) than that of the collateral sesamoidean ligament (89.48%±5.8; P = .0008) and the middle phalanx (85.72%±3.67; P = .0008). Under polarized light microscopy, it showed a slight heterogeneous pattern of birefringence, with angle-related changes. Elastic fibres were more numerous (21.76%±8.72) than in the collateral sesamoidean ligament (0.28%±0.45), or deep digital flexor tendon (0.04%±0.02); and were more densely packed. Mean cell count was higher for the T-ligament than for other tissues (P = .0007). Blood vessels were identified in the T-ligament and were penetrating the deep digital flexor tendon (8/10 limbs, 5/5 horses). In conclusion, the T-ligament looked like a vinculum for the deep digital flexor tendon, with a central elastic core, surrounding loose connective tissue and blood vessels. It is not a ligament. Its clinical relevance still needs to be determined.

Bacillus licheniformis septicemia in a very-low-birth-weight neonate: a case report.

Nosocomial infections in neonatal intensive care units are a preoccupying issue. Bacillus sp. can be pathogenic in immuno-compromised hosts, including premature infants. Central catheters and mechanical ventilation are potential sources of infection. We report for the first time a case of Bacillus licheniformis bacteremia in a premature infant. Recovery necessitated treatment with vancomycin and cefotaxime in combination with removal of the central catheter.

[Congenital tuberculosis in preterm neonate: a case report]. / Tuberculose congénitale chez le nouveau-né prématuré : à propos d'un cas.

Congenital tuberculosis is a rare but severe disease. Diagnosis is often delayed, especially in preterm neonates. We report a premature infant born after 27 weeks of gestation and in vitro fertilization. Tuberculosis was suspected after 112 days of life in view of sepsis, respiratory distress, and the discovery of maternal tuberculosis. Mycobacterium tuberculosis was isolated in endotracheal aspirates, gastric aspirates, and stools. The infant initially received four antitubercular antibiotics over 3 months, then two antibiotics over 9 months. A wide screening for a possible nosocomial transmission from this index case was set up. At the chronological age of 2 years, the baby is healthy without after-effects and no secondary cases were diagnosed. This article recalls the difficulty diagnosing congenital tuberculosis, particularly in preterm neonates. It also underlines the need to raise and eliminate the diagnosis of tuberculosis in an infertile woman.

Thoracic ultrasound accuracy for the investigation of initial neonatal respiratory distress.

Thoracic ultrasound (TUS) is increasingly studied in neonatal respiratory distress but chest x-ray (CXR) remains the first-line exam. We aimed to evaluate its diagnostic performance for the investigation of unselected causes of neonatal respiratory distress in daily practice. We conducted a descriptive, prospective, and single-center diagnostic accuracy study in a tertiary hospital, including term and preterm newborns who needed a CXR because of respiratory conditions occurring at birth or during the first 24h of life. TUS was compared to the reference diagnosis, which was the association between the CXR results, the clinical initial context, and the patient's outcome. Fifty-two newborns were included and 104 hemi-thorax ultrasounds were analyzed. Sensitivity, specificity, positive and negative predictive values (PPV, NPV), diagnosis accuracy, as well as the positive and negative likelihood ratio of TUSs were 100% for respiratory distress syndrome (RDS), transient tachypnea of newborn (TTN), pneumomediastinum, meconium aspiration syndrome, and absence of pulmonary disease. TUS also showed 100% sensitivity and NPV for pneumothorax, but specificity was 97% and PPV was 50%. Kappa concordance between TUS and either CXR alone or the radiological/clinical gold standard was 0.79 and 0.95, respectively. CONCLUSION: TUS at the newborn's bedside is efficient for investigating the main neonatal respiratory diseases, especially for the confirmation of RDS or TTN and for the exclusion of differential diagnosis or complications.

[Transcutaneous bilirubin measurement in preterm infants]. / Estimation de la bilirubinémie par méthode transcutanée chez le nouveau-né prématuré.

UNLABELLED: Transcutaneous bilirubinometry is an effective screening tool for neonatal jaundice in full-term babies. But its accuracy is not shown yet in preterm infants. METHODOLOGY: We carried out a prospective study in a neonatal intensive care unit. The study included 47 preterm infants. From birth, a transcutaneous bilirubin measurement (BTc) using the BiliCheck was made on the forehead of each newborn every 8 h. Blood sampling for determination of total serum bilirubin (BS) was combined with BTc: 1) if value of BTc was higher than limits values for phototherapy; 2) on the second day of life and 3) 4 hours after cessation of phototherapy. RESULTS: Mean gestational age was 30 week and mean birth weight was 1419 g. We studied 151 pairs of BTc and BS. Mean values obtained by BTc and BS were respectively 160.6+/-50 mumol/L and 190.6+/-61.4 mumol/L. A significant correlation between BTc and BS was found. But the limits of agreement were very wide. The negative predictive value (NPV) of BTc was above 90% in each group of gestational age. DISCUSSION: The need for phototherapy cannot be determined by BTc in preterm infants. But the BTc is reliable when its value is under the limits for phototherapy. CONCLUSION: With a very high incidence of neonatal jaundice (87%) in our cohort, a value of BTc under the limits for phototherapy has a good NPV in preterm infants.

Phase I trial of murine monoclonal antibody L6 in breast, colon, ovarian, and lung cancer.

Murine monoclonal antibody (MAb) L6 binds to an antigen expressed on the surface of breast, colon, ovary, and nonsmall-cell lung cancer. This antibody effects antibody-dependent cellular cytotoxicity (ADCC) with human mononuclear cells and complement-dependent cytotoxicity (CDC) with human complement. Because of these activities, we conducted a phase I trial of MAb L6 in patients with advanced cancer. Nineteen patients whose tumors highly expressed antigen were selected for this trial. Eighteen were evaluable. MAb L6 was administered at dose levels ranging from 5 mg/m2/d to 400 mg/m2/d for 7 days and was well tolerated. The only side effects detected were fever and headaches at the highest dose levels. The serum half-life of L6 was directly related to dose and ranged from a mean of 7.7 hours at 5 mg/m2/d to 29.1 hours at 400 mg/m2/d. Peak serum concentrations ranged from 0.22 micrograms/mL to 362 micrograms/mL. Biopsies at the end of treatment showed L6 to localize well to tumor cells with apparent in vivo saturation occurring at dose levels above 100 mg/m2/d. Thirteen patients formed human antimouse antibodies (HAMA), some as early as day 13. One patient with recurrent breast cancer on the chest wall achieved a complete remission. The response was first noted at 5 weeks and a pathologic complete remission occurred at 14 weeks. Because of its favorable binding properties and the encouraging clinical effect observed, future evaluation of this MAb appears warranted.

Phase I study of carboplatin given on a five-day intravenous schedule.

Twenty-six adult patients were entered in a phase I trial of carboplatin, a new cisplatin derivative with reduced potential for nephrotoxicity. All patients had solid tumors and the median World Health Organization performance score was 2 (0-3). Twelve patients had not received prior chemotherapy. The drug was administered as a 15-minute IV infusion, without pre- or posthydration, at daily doses of 40-125 mg/m2 for five consecutive days. Antiemetics were given only if needed. Thrombocytopenia and neutropenia were dose related and dose limiting. One patient died from septic shock at the highest dose level. Nonhemolytic anemia was also encountered. Nausea and vomiting were experienced by most patients but gastrointestinal intolerance was severe in only two patients. One patient had hypercreatininemia, which was minor and rapidly reversible. Other toxic effects consisted of negligible fatigue, paresthesia, pruritus, local pain, stomatitis, headache, and alopecia. Although none of the patients achieved a partial or complete response, antitumor effect was strongly suggested in two patients with thyroid and cervix cancer, respectively. Carboplatin is an attractive candidate for phase II trials. In good-risk patients, such trials could be initiated at a daily dose of 100 mg/m2 for five consecutive days every five to six weeks.

Ifosfamide plus doxorubicin in metastatic adult sarcomas: a multi-institutional phase II trial.

Between April 1986 and March 1987, 42 patients with advanced sarcoma were entered in this multi-institutional trial evaluating ifosfamide plus doxorubicin. The majority of patients had leiomyosarcoma and malignant fibrous histiocytoma although two patients with sarcomas of osseous origin were included. Doxorubicin was administered at a dosage of 60 mg/m2 by continuous push and ifosfamide 5.0 g/m2 by continuous infusion over 24 hours with mesna (7.5 g2 over 36 hours) with courses repeated every 3 weeks until progression, toxicity cumulative doxorubicin dosage of 450 mg/m2. Overall, 15 (36%) patients demonstrated objective remissions including three complete and 12 partial remissions (95% confidence limits, 21.5% to 52.0%). The median duration of remission was 7.0 months and the median survival time for all eligible patients was 8.0 months. Toxicity was predominantly hematologic with the median leukocyte nadir being 1,300 per microliter of blood and documented sepsis in six patients. These data support activity for ifosfamide plus doxorubicin in patients with advanced sarcoma, but the actual contribution of ifosfamide needs to be evaluated through prospective randomized trials which are currently underway.

Ifosfamide and mesna: marginally active in patients with advanced carcinoma of the pancreas.

Ifosfamide, an analogue of cyclophosphamide, has therapeutic activity against a wide variety of human malignancies. In a phase II trial in carcinoma of the pancreas, we treated 31 patients who had not received prior chemotherapy with a median ifosfamide dose of 2 g/m2/d (range, 1.5 to 2 g/m2/d) administered intravenously (IV) over one hour for five consecutive days every 3 weeks. 2-mercaptoethane sulphonate (mesna), an acrolein antagonist with known uroendothelial protective properties, was administered IV at a dose of 400 mg/m2 over 15 minutes before the daily dose of ifosfamide and repeated every four hours for two additional doses. Among 30 evaluable patients, one patient achieved a complete remission (26+ months) and another patient had a partial remission (4 months). The median duration of survival of all patients from the start of ifosfamide therapy was only 3 months (range, 1 to 26+ months). Treatments were generally well tolerated. The most common toxic effects included granulocytopenia, nausea and vomiting, malaise, anorexia, and mild hematuria. Mesna offers an adequate protection against uroendothelial injury caused by ifosfamide. Despite the previously reported response rate of greater than 20% at the same or lower doses of ifosfamide in other studies, our data suggest that ifosfamide is only marginally active against cancer of the pancreas and appears to be of minimal value in the treatment of patients with this tumor.

Etoposide combined with cyclophosphamide plus vincristine compared with doxorubicin plus cyclophosphamide plus vincristine and with high-dose cyclophosphamide plus vincristine in the treatment of small-cell carcinoma of the lung: a randomized trial of the Bristol Lung Cancer Study Group.

A total of 353 patients with previously untreated small-cell lung cancer (SCLC) were accrued in this multicenter trial. Patients were randomly assigned to receive one of the following three regimens: cyclophosphamide 1,000 mg/m2 intravenously (IV) day 1, vincristine 1.4 mg/m2 IV day 1, and etoposide 50 mg/m2 IV day 1, followed by etoposide 100 mg/m2/day orally days 2 through 5 (CEV); cyclophosphamide 1,000 mg/m2 IV day 1, vincristine 1.4 mg/m2 IV day 1, and doxorubicin 50 mg/m2 IV day 1 (CAV); cyclophosphamide 2,000 mg/m2 day 1 and vincristine 1.4 mg/m2 IV day 1 (CV). Cycles were repeated every 3 weeks. Treatment groups were comparable with respect to extent of disease, age, sex, performance status, and metastatic sites. No significant differences in response rates, response duration, or survival could be detected in limited disease, although there appeared to be a trend favoring CEV. Among extensive-disease patients, response duration on the CEV regimen was longer than on the CV regimen or the CAV program (P less than .001). The superiority of the CEV regimen was also demonstrated in the survival analysis in which differences attained statistical significance (P = .01). In this group the median survival was increased from 29 weeks on CV to 31 weeks on CAV and 39 weeks on CEV. Myelosuppression was the most frequent toxicity. It was more severe with CV than CEV or CAV. Most nonhematologic side effects were comparable among the three treatment groups. However, the high doses of cyclophosphamide in the CV regimen produced a higher incidence of hemorrhagic cystitis than in the CEV or CAV programs (P less than .001). Cardiotoxicity only occurred in the CAV group (P = .05). The addition of etoposide to the CV regimen resulted in significantly longer response duration and survival without increased toxicity. Similarly, the substitution of etoposide for the doxorubicin in the CAV regimen was associated with prolonged survival and reduced cardiotoxicity.

Phase I trial of murine monoclonal antibody L6 in combination with subcutaneous interleukin-2 in patients with advanced carcinoma of the breast, colorectum, and lung.

PURPOSE: A phase I trial was undertaken to determine the toxicity and biologic effects of a combination of murine monoclonal antibody L6 (MoAb L6) plus subcutaneous (SC) interleukin-2 (IL-2). PATIENTS AND METHODS: Fifteen patients with refractory adenocarcinoma (five breast, five lung, five colorectal), received L6 at 200 mg/m2 intravenously (IV) daily on days 1 to 7, followed by a 1-week rest period. IL-2 was given at either 2, 3, or 4.5 x 10(6) U/m2 daily doses times 4 days for a total duration of 3 weeks. RESULTS: Side effects of L6 consisted of mild fever and chills along with a rash and serum sickness in one patient. One patient developed dyspnea and urticaria, that resolved with antihistamines. Maximum-tolerated dose (MTD) of SC IL-2 was 3 x 10(6) U/m2, with dose-limiting toxicities that consisted of grade 4 fatigue and dyspnea. Significant decreases in complement levels along with increases in absolute lymphocyte count and eosinophil count were observed. Mean antibody-dependent cellular cytotoxicity from mononuclear cells taken from patients who received IL-2 was elevated significantly compared with baseline in all patients independent of IL-2 dose (P less than .05). Serum IL-2 levels were elevated in 13 of 14 patients (range, 0.9 to 100 U/mL). Human antimouse antibody (HAMA) titers were elevated in nine of 14 (64%) patients who were tested between 3 and 8 weeks after L6 infusion. One patient with breast cancer had a transient mixed response, and one patient with colorectal cancer had a partial response. CONCLUSIONS: L6 and SC IL-2 were well tolerated in the majority of patients when given in the outpatient setting. In view of the clinical efficacy of this combination, more phase II trials are warranted.

Megestrol acetate: clinical experience.

PIP: The use of megestrol acetate in treatment of malignancy (endometrial carcinoma, ovarian cancer, prostate cancer, breast cancer, renal cell carcinoma, malignant melanoma), endometrial hyperplasia, benign prostatic hypertrophy, contraception, anorexia, cachexia and weight loss is reviewed, concluding with a toxicity profile. Megestrol acetate was introduced in 1971 for treatment of endometrial carcinoma. Megestrol acetate is probably effective in proportion to the number of cytoplasmic progesterone receptors, but it has not been tested in a Phase III trial. For ovarian cancer it has been reported to be effective in 1 trail at doses of 800 mg/day. Prostate cancer, although difficult to assess, responds to megestrol acetate at doses of 120 mg/day because of its suppression of gonadotropins, its inhibition of 5alpha-reductase and its binding to the dihydrotestosterone receptor. Megestrol acetate permits a lower dose of diethylstilbestrol, and thus lower toxicity. There is apparently a dose-response between megestrol acetate and breast cancer, along with a response dependent on the number and type of estrogen and progestin receptors. Responses are better in postmenopausal women, and additive with other agents such as tamoxifen and mitomycin C. The medium duration of effect is 6-8 months. It has no effect on renal cancer or malignant melanoma. Megestrol acetate can be considered as an effective medical alternative to surgery for endometrial hyperplasia or benign prostatic hypertrophy. As a contraceptive in inhibits sperm transport rather than ovulation, but also causes irregular bleeding. Megestrol acetate has few side effects, and has the advantage of stimulating appetite and weight gain, a benefit in cancer patients.^ieng

Overview of hormonal therapy in advanced breast cancer.

Hormonal therapy of breast cancer is widely used and effective. Although never curative in advanced disease, significant palliation and durable remissions can be obtained with a wide variety of hormonal manipulations. Historically, surgical ablation was used to reduce endogenous hormone levels, but this invasive procedure has been largely supplanted by drugs that reduce hormone secretion or block steroid hormone activity. A number of such antagonists are available, with tamoxifen probably the most widely used. Response can also be achieved with hormone agonists. Estrogens and androgens or their congeners have about the same level of activity as surgical ablation or drug antagonists (20% to 30% overall response rate). The progestins, another class of agonists, are also effective in the palliation of advanced breast cancer. Megestrol acetate, in part because of its oral formulation, is probably the most commonly used progestational drug for the treatment of breast cancer. Reports of 16 trials involving 1,342 patients show a response rate of 26% in patients with advanced breast cancer treated with megestrol acetate. The drug has proved active in a small number of male patients and, in randomized trials, it has been shown to be comparable with tamoxifen in efficacy (30% response for megestrol acetate v 35% for tamoxifen). Studies are currently under way to evaluate the possibility that high doses of megestrol acetate may increase response rates, and to determine whether weight gain, a well-described effect of this drug, may prove beneficial in cancer treatment.

Drug discovery and development in the pharmaceutical industry.

The discovery and development of new anticancer drugs is a complex and largely empirical process. New compounds can be discovered by screening, modification of existing compounds, rational drug design, and serendipitous basic research observations. Selection of compounds for clinical trials depends on assays of uncertain predictive value. In the pharmaceutical industry, priorities for development of potentially active entities are set and available resources allocated based on the availability and cost of supplies, patent status, potential spectrum of activity, ability to meet regulatory requirements, and market assessments. Competition for resources also occurs from noncancer drugs, eg, cardiovascular agents. Clinical development (testing and approval for commercial distribution) requires close attention to the requirements of national regulatory agencies such as the United States Food and Drug Administration. The arbitrary nature by which compounds with antitumor potential are chosen for development means that some that would be useful never reach clinical trial and others are never made generally available. This article reviews the decision making process in the pharmaceutical industry by which compounds are identified and selected for clinical trial, the regulations in the United States that govern such trials, and what is required to have the drug approved for commercial distribution.

Single-agent ifosfamide studies in sarcomas of soft tissue and bone: the M.D. Anderson experience.

We have used ifosfamide to treat patients with sarcomas in four completed single-agent protocols and one pilot study since 1985. All the studies have used either N-acetyl-L-cysteine (NAC) or mesna as a uroprotective agent, except in one arm of one study where hydration alone was employed. Mesna has proven superior to NAC in providing protection against ifosfamide-induced hematuria. Mesna given as a loading dose followed by continuous 24-h infusion has been effective and most practical in this regard. Ifosfamide has demonstrated clinically useful antitumor activity in our hands against most sarcoma subtypes. Our studies suggest a dose-response relationship for ifosfamide. At a total dose of 6 g/m2 per course, the overall response rate was 10%; at 10 g/m2 per course, it rose to 21%. Future clinical trials will determine ifosfamide's role in combination chemotherapy and more clearly define the best schedule or schedules for the uroprotective administration of mesna.

Combination of dacarbazine and mitomycin in advanced colorectal cancer.

Twenty evaluable patients with advanced measurable colorectal cancer received 3-week courses of a combination of IV dacarbazine 300 mg/m2/day from day 1 to day 5 and IV mitomycin 2 mg/m2/day from day 1 to day 5. Fourteen of these patients had had no prior chemotherapy and received two or more courses of this two-drug regimen. None of the patients achieved complete or partial response. Severe to life-threatening myelosuppression, was encountered in patients with prior radiotherapy and or prior chemotherapy, and/or in patients with a Karnofsky score less than or equal to 70. Hematologic toxicity was mild in the other patients. Nonhematologic toxic effects were generally mild to moderate and consisted essentially in nausea and vomiting. It is concluded that in our hands the regimen selected for this trial has no significant antitumor activity in advanced colorectal cancer.