Declining bone mass in men with chronic pulmonary disease: contribution of glucocorticoid treatment, body mass index, and gonadal function

BACKGROUND

Men with chronic lung disease (CLD) are at risk for osteoporosis, but the relative contributions of their chronic pulmonary disease, glucocorticoid therapy, and other factors toward loss of bone has not been established. Understanding the relative importance of these factors would assist in selecting patients for bone densitometry screening and in policy decisions regarding Medicare reimbursement.

OBJECTIVE

To identify patients with CLD who are most likely to benefit from bone densitometry screening based on clinical and biochemical measures.

DESIGN

Cross-sectional medical survey.

PATIENTS

Patients with CLD who were treated with either oral, inhaled, or no glucocorticoid therapy. A control group without lung disease was recruited from the same clinic population.

MEASUREMENTS

Dual-energy X-ray absorptiometry was obtained for each group, and the association between bone mass and clinical variables, glucocorticoid use, gonadal hormones, and biochemical markers of bone metabolism was determined.

RESULTS

Osteoporosis (a T score < -2.5 at the hip or spine) was five times as likely in patients with CLD as in control subjects. Although the prevalence of osteoporosis was higher (ninefold) after chronic glucocorticoid therapy, patients with CLD who had never been treated with glucocorticoids had a substantial (fourfold) risk of osteoporosis. Chronic inhaled glucocorticoid therapy offered no protection from bone loss compared to treatment with oral glucocorticoids. Of the clinical and biochemical measures that were obtained, bone mass was weakly correlated with body mass index (BMI), serum estradiol-17beta, and N-telopeptide, but not with testosterone, alkaline phosphatase, bone-specific alkaline phosphatase, or osteocalcin.

CONCLUSION

Patients with CLD should be considered for bone densitometry screening regardless of glucocorticoid use. Those patients with a low BMI and/or decreased serum estradiol-17beta comprise a subgroup with increased risk for osteoporosis.

Tc-99m sestamibi scintimammography in the mammographically dense breast

PURPOSE

The mammographically dense breast or the "difficult-to-interpret mammogram" poses significant clinical and diagnostic imaging concerns. From our experience using Tc-99m sestamibi mammography in more than 650 patients, we share our experience in a pictorial manner and include suggested indications and limitations of this exciting new technique. Examples of Tc-99m sestamibi imaging in six patients with mammographically dense breasts are presented.

MATERIALS AND METHODS

All patient examinations were ordered clinically for various indications. Comparison radiographic mammography and, when available, confirmatory pathologic analysis were also done. The examples were chosen from our experience with more than 650 patients at two university hospitals and one outpatient imaging center.

RESULTS

Of the six examples presented, four had cancer, one had fibrosis after chemotherapy for ductal cell carcinoma, and one had no evidence of cancer. Tc-99m sestamibi imaging showed no increased uptake in the one patient with no tumor and various degrees of uptake in the other five patients.

CONCLUSIONS

Six examples from our clinical experience show the usefulness of Tc-99m sestamibi imaging in patients with mammographically dense breasts. The ability to identify a malignancy or its absence supports the continued use of this procedure in these patients.

Usefulness of fructosamine for monitoring outpatients with diabetes

BACKGROUND

Measurements of total glycohemoglobin (glycoHb) or hemoglobin A1c are routinely used to evaluate intermediate-to-long term glycemic control in patients with diabetes. However, despite the recent availability of more rapid methods for glycohemoglobin determination, it remains difficult in many institutions to obtain same-day glycoHb determinations in time to assist physicians with management of outpatients with diabetes. Hence, we investigated whether fructosamine, which reflects very recent (2 to 3 weeks) glycemic control and which can be assayed more rapidly in our laboratory, could serve as a useful adjunct to glycoHb for management of these patients.

METHODS

Diabetes control in outpatients managed using fructosamine, fasting serum glucose, and glycoHb (concentrations from the prior visit) was compared with that for outpatients monitored using fasting serum glucose and prior glycoHb alone. The relative usefulness of fructosamine, current and prior glycoHb, and "fasting" serum glucose for evaluation and management of outpatients with diabetes was compared. In addition, the acceptance of fructosamine by physicians was evaluated by a questionnaire.

RESULTS

Same-day fructosamine concentrations correlated better with current glycoHb than did either prior glycoHb or current fasting serum glucose concentrations. However, the availability of same-day fructosamine results did not objectively improve diabetes control compared with that obtained using only fasting serum glucose values and prior glycoHb concentrations. Nonetheless, most examining physicians stated that same-day fructosamine concentrations helped them significantly with diabetes management, primarily because many patients do not adequately monitor home blood glucose levels.

CONCLUSIONS

Fructosamine may be a useful adjunctive test for management of outpatients with diabetes in situations where it is not practical to obtain same-day glycoHb concentrations, for patients less compliant with home glucose monitoring, or where recent changes in insulin dose or clinical presentation might not be reflected in the glycoHb levels.

Immunotherapy of advanced malignancy by direct gene transfer of an interleukin-2 DNA/DMRIE/DOPE lipid complex: phase I/II experience

PURPOSE

We have completed a phase I study, followed by three phase I/II studies, in patients with metastatic melanoma, renal cell carcinoma (RCC), and sarcoma in order to evaluate the safety, toxicity, and antitumor activity of Leuvectin (Vical Inc, San Diego, CA), a gene transfer product containing a plasmid encoding human interleukin (IL)-2 formulated with the cationic lipid 1, 2-dimyristyloxypropyl-3-dimethyl-hydroxyethyl ammonium bromide/dioleyl-phosphatidyl-ethanolamine (DMRIE/DOPE) and administered intratumorally.

PATIENTS AND METHODS

Twenty-four patients were treated in the phase I study. Leuvectin doses were 10 microg, 30 microg, or 300 microg weekly for 6 weeks. In three subsequent phase I/II studies, a total of 52 patients (18 with melanoma, 17 with RCC, and 17 with sarcoma) were treated with further escalating doses of Leuvectin: 300 microg twice a week for 3 weeks, 750 microg weekly for 6 weeks, and 1,500 microg weekly for 6 weeks.

RESULTS

There were no drug-related grade 4 toxicities and only one grade 3 toxicity, but the majority of patients experienced mild constitutional symptoms after treatment. In the phase I/II studies, 45 patients were assessable for response (14 with RCC, 16 with melanoma, and 15 with sarcoma). Two patients with RCC and one with melanoma have achieved partial responses lasting from 16 to 19 months and continuing. In addition, two RCC, three melanoma, and six sarcoma patients had stable disease lasting from 3 to 18 months and continuing. The plasmid was detected by polymerase chain reaction assay in the posttreatment samples of 29 of 46 evaluated patients. Immunohistochemistry studies on serial biopsy specimens showed increased IL-2 expression and CD8(+) infiltration after treatment in the tumor samples of several patients (12 and 16, respectively).

CONCLUSION

Direct intratumoral injection of Leuvectin is a safe and possibly effective immunotherapeutic approach in the treatment of certain tumor types.

North Central Cancer Treatment Group Phase II study of 5-fluorouracil and high-dose levamisole for gastric and gastroesophageal cancer using survival as the primary endpoint of efficacy

At present there is no established standard chemotherapy for advanced gastric cancer. Combination regimens have yielded response rates at times exceeding 50% but with no improvement in survival compared to single agents. This study examined the role of 5-fluorouracil and high-dose levamisole in a phase II setting using survival as the main endpoint. Patients with advanced carcinomas of the stomach or gastroesophageal junction were treated with 5-fluorouracil, 450 mg/m2 IV days 1 to 5, and levamisole, 100 mg/m2 orally three times daily on days 1 to 3, and 50 mg/m2 tid days 4 to 5 every 5 weeks. To allow more rapid accrual and to study a population that more accurately reflects the makeup of patients treated in clinical practice, patients with both measurable and nonmeasurable disease were entered in this study. Two of fifteen (13%) patients with measurable disease experienced a partial response to treatment. The adjusted 1-year survival rate for the 44 patients entered was 29.6%, which is similar to the historical 1-year survival of 30% observed in a group of nearly 400 patients treated in prior North Central Cancer Treatment Group studies. This regimen offers no improvement in therapeutic activity for advanced gastric cancer. This study design, however, allows rapid screening of phase II regimens in patients who would usually be candidates for phase III trials.

Osteoclastogenesis is repressed by mechanical strain in an in vitro model

Functional loading provides a site-specific signal for the regulation of bone mass and morphology. To determine if strain can inhibit the resorptive component of bone remodeling, osteoclast formation was assessed in marrow cultures plated on flexible membranes subjected to 5% strain for 10 cycles/minute, 24 hours per day. Cultures strained during days 2 through 7 inhibited osteoclast formation to 61+/-7% of control cultures (p < 0.05), a degree of inhibition similar to that observed when the cultures were subjected to strains during only days 2 through 4 but also evaluated on day 7 (67+/-4% of control; p < 0.05). In contrast, straining of cultures during days 5 through 7 had little influence on inhibiting the formation of osteoclasts (94+/-5% of control; no significant difference). The nonuniformly strained substrate was subdivided into three concentric rings. and cultures were used to examine the site-specificity of the inhibition caused by strain. Osteoclast formation in the outermost boundary, which was distended from 3.6 to 5%, was 41+/-7% of that observed in outer regions of control wells. The inhibitory potential of mechanical strain was reduced within the middle ring (73+/-6% of control osteoclasts: p < 0.01), where the strain ranged from 0.2 to 3.6%. The central region, which experienced strains equivalent to those in the middle ring (0.2 to -4% strain), showed inhibition of osteoclast formation to a similar degree (75+/-6% of control). Media harvested from strained cultures failed to inhibit osteoclast formation in unstrained cultures; this implies that the inhibitory effect of strain depended on the direct interaction of the cell with the substrate rather than by a humoral factor. A second device, where a uniform strain was delivered at 1.8% throughout the entire plate, inhibited osteoclast recruitment to 48+/-3.6%, emphasizing that uniform strain in the absence of shear stress constrains osteoclast recruitment. These in vitro experiments can but model the complex environment generated by in vivo mechanical strains: however, they provide the first direct evidence that strain must be considered as inhibitory to osteoclast recruitment.

Familial occurrence of carcinoid tumors and association with other malignant neoplasms

Carcinoid tumors are generally thought to be sporadic, except for a small proportion that occur as a part of multiple endocrine neoplasia syndromes. Data regarding the familial occurrence of carcinoid as well as its potential association with other neoplasms are limited. A chart review was conducted on patients indexed for malignant carcinoid tumor of the gastrointestinal tract seen at the Mayo Clinic between 1988 and 1996. A survey of family history of malignancies and personal history of other tumors was mailed to all eligible patients. Data for 245 patients were analyzed. Observed rates of carcinoids and other malignancies were compared with Surveillance, Epidemiology, and End Results data. Estimates of the cumulative probability for first-degree relatives developing a carcinoid tumor were calculated. Nine (3.7%) patients with carcinoid tumor had at least one first-degree relative with the same malignancy. The rate of carcinoid tumor in first-degree relatives of probands was higher (P < 0.0001) than expected based on the Surveillance, Epidemiology, and End Results population data. Cumulative probability in a first-degree relative for developing a carcinoid was calculated to be 1.5% at age 80. There was an increased risk for developing a carcinoid tumor among first-degree relatives of patients with carcinoid. Neither patients with carcinoid nor their first-degree relatives had an increased incidence of other malignancies.

Thoracoscopic splanchnicectomy: pilot evaluation of a simple alternative for chronic pancreatic pain control

Achieving adequate pain control in patients with chronic pancreatitis remains a surgical challenge. The quest for a procedure that retains all of the residual pancreatic tissue in the absence of ductal dilatation remains elusive. This study sought to evaluate the feasibility and efficacy of thoracoscopic splanchnicectomy and attempted to outline the surgical anatomy appropriate to an adequate denervation. Of 17 patients considered suitable for the procedure, 16 had a sucessful outcome, which was statistically significant (p < 0.001). The longest follow-up of 30 months suggests that the procedure may be more enduring than percutaneous procedures. However, the surgical anatomy is not predictable owing to the racemose arrangement of the splanchnic fibers, and a long pleurotomy with transection of all medial fibers is necessary to effect denervation. Thoracoscopic splanchnicectomy may effect immediate pain relief with negligible morbidity and absent mortality. Although the follow-up period is short, the patient with the longest follow-up remains pain-free at 30 months. This procedure warrants scrutiny for its role in long-term pancreatic pain control.

Role of NFkappaB in the regulation of macrophage colony stimulating factor by tumor necrosis factor-alpha in ST2 bone stromal cells

Expression of MCSF in bone is important to the regulation of osteoclastogenesis. We show here that tumor necrosis factor-alpha (TNFalpha) increases the production of both soluble (sMCSF) and membrane-bound (mMCSF) macrophage colony stimulating factor by ST2 bone stromal cells. Treatment of ST2 cells with TNFalpha caused sMCSF levels to increase by 394+/-5% from basal; mMCSF rose by 316+/-66% from 30+/-10 per 100,000 cells in the same time. These increases were consistent with increased expression of mRNAs encoding both isoforms. Increases in MCSF mRNA are also seen after stimulation with dexamethasone. To investigate the potential role of NFkappaB in this TNFalpha effect, we treated cells with sodium salicylate (NaS), an inhibitor of NFkappaB translocation. NaS decreased TNFalpha-stimulated NFkappaB activation by 50% as assessed by EMSA. Despite inhibition of NFkappaB signaling, NaS enhanced TNFalpha-stimulated MCSF secretion and did not prevent TNFalpha-stimulated increases in sMCSF mRNA, suggesting that NFkappaB was not involved in TNFalpha effect on the gene. TNFalpha failed to stimulate transcription of a 774 nucleotide MCSF promoter-luciferase reporter transfected into ST2 cells which contained the NFkappaB consensus sequence. Deletion of the seven nucleotides containing the NFkappaB homology response sequence from the MCSF promoter increased basal gene transcription by twofold. TNFalpha thus contributes to an osteoclastogenic environment through upregulation of bone expression of both MCSF isoforms. Our data suggests that NFkappaB is not the major signaling pathway through which this occurs.

Phase I trial of dolastatin-10 (NSC 376128) in patients with advanced solid tumors

Dolastatin-10 (dola-10) is a potent antimitotic peptide, isolated from the marine mollusk Dolabela auricularia, that inhibits tubulin polymerization. Preclinical studies of dola-10 have demonstrated activity against a variety of murine and human tumors in cell cultures and mice models. The purpose of this Phase I clinical trial was to characterize the maximum tolerated dose, pharmacokinetics, and biological effects of dola-10 in patients with advanced solid tumors. Escalating doses of dola-10 were administered as an i.v. bolus every 21 days, using a modified Fibonacci dose escalation schema. Pharmacokinetic studies were performed with the first treatment cycle. Neurological testing was performed on each patient prior to treatment with dola-10, at 6 weeks and at study termination. Thirty eligible patients received a total of 94 cycles (median, 2 cycles; maximum, 14 cycles) of dola-10 at doses ranging from 65 to 455 microg/m2. Dose-limiting toxicity of granulocytopenia was seen at 455 microg/m2 for minimally pretreated patients (two or fewer prior chemotherapy regimens) and 325 microg/m2 for heavily pretreated patients (more than two prior chemotherapy regimens). Nonhematological toxicity was generally mild. Local irritation at the drug injection site was mild and not dose dependent. Nine patients developed new or increased symptoms of mild peripheral sensory neuropathy that was not dose limiting. This toxicity was more frequent in patients with preexisting peripheral neuropathies. Pharmacokinetic studies demonstrated a rapid drug distribution with a prolonged plasma elimination phase (t 1/2z = 320 min). The area under the concentration-time curve increased in proportion to administered dose, whereas the clearance remained constant over the doses studied. Correlation analysis demonstrated a strong relationship between dola-10 area under the concentration-time curve values and decrease from baseline for leukocyte counts. In conclusion, dola-10 administered every 3 weeks as a peripheral i.v. bolus is well tolerated with dose-limiting toxicity of granulocytopenia. The maximum tolerated dose (and recommended Phase II starting dose) is 400 microg/m2 for patients with minimal prior treatment (two or fewer prior chemotherapy regimens) and 325 microg/m2 for patients who are heavily pretreated (more than two prior chemotherapy regimens).

A case of urachal remnant presenting as acute abdominal pain

A 30-year-old male presented to the Emergency Department, over sequential visits, with abdominal complaints. The patient's presenting history and physical examination were mistakenly diagnosed variously as gastroenteritis, omphalitis, and appendicitis. Ultimately, the diagnosis of urachal fistula was made at surgery. This case is discussed in light of prior published experiences with this disease entity.

Octreotide acetate long-acting formulation versus open-label subcutaneous octreotide acetate in malignant carcinoid syndrome

PURPOSE

Subcutaneous (SC) octreotide acetate effectively relieves the diarrhea and flushing associated with carcinoid syndrome but requires long-term multiple injections daily. A microencapsulated long-acting formulation (LAR) of octreotide acetate has been developed for once-monthly intramuscular dosing.

PATIENTS AND METHODS

A randomized trial compared double-blinded octreotide LAR at 10, 20, and 30 mg every 4 weeks with open-label SC octreotide every 8 hours for the treatment of carcinoid syndrome. Seventy-nine patients controlled with treatment of SC octreotide 0.3 to 0.9 mg/d whose symptoms returned during a washout period and who returned for at least the week 20 evaluation constituted the efficacy-assessable population.

RESULTS

Complete or partial treatment success was comparable in each of the four arms of the study (SC, 58.3%; 10 mg, 66.7%; 20 mg, 71.4%; 30 mg, 61.9%; P> or =.72 for all pairwise comparisons). Control of stool frequency was similar in all treatment groups. Flushing episodes were best controlled in the 20-mg LAR and SC groups; the 10-mg LAR treatment was least effective in the control of flushing. Treatment was well tolerated by patients in all four groups.

CONCLUSION

Once octreotide steady-state concentrations are achieved, octreotide LAR controls the symptoms of carcinoid syndrome at least as well as SC octreotide. A starting dose of 20 mg of octreotide LAR is recommended. Supplemental SC octreotide is needed for approximately 2 weeks after initiation of octreotide LAR treatment. Occasional rescue SC injections may be required for possibly 2 to 3 months until steady-state octreotide levels from the LAR formulation are achieved.

Cirrhotic ascites, ovarian carcinoma, and CA-125

We describe two postmenopausal women with ascites and elevated CA-125 level, a serologic marker used to detect ovarian cancer. Both patients had unrecognized liver disease but underwent surgical exploration for suspected ovarian disease, which subsequently revealed benign pelvic organs. Elevated serum CA-125 levels have been reported in many patients with ascites due to liver disease and cirrhosis. Thus, the presence of both ascites and an elevated CA-125 level mandates a thorough elevation for liver disease as well as for a possibility of ovarian carcinoma. These cases outline the common finding and provide insight into the management of patients with ascites and elevated CA-125 values.

Effects of tamoxifen on striatal dopamine and 5-hydroxytryptamine release in freely moving male rats: an in-vivo microdialysis investigation

Recent studies indicating interaction of oestrogens with central cholinergic, dopaminergic and 5-HTergic systems have led to the assumption of a protective role of oestrogens in certain neurodegenerative disorders. The non-steroidal drug tamoxifen, a mixed oestrogen agonist-antagonist, has been shown to modulate central nervous system functions in the corpus striatum. In this study we used a microdialysis technique to examine the effects of tamoxifen upon the striatal dopaminergic and 5-HTergic systems in intact freely moving male rats. The extracellular levels of dopamine, 3,4-dihydroxyphenylacetic acid, homovanillic acid and 5-hydroxyindoleacetic acid were measured after intraperitoneal administration of either the control or tamoxifen, and were compared with their corresponding baseline levels. Significant 25-35% increases in the baseline levels of dopamine and 3,4-dihydroxyphenylacetic acid were observed after the highest doses of tamoxifen (1.5 mg kg(-1) and 30 mg kg(-1), respectively), whereas the lowest dose of tamoxifen (0.3 mg kg(-1)) elevated dopamine and 3,4-dihydroxyphenylacetic acid levels by a detectable 15% of the basal. In addition, the ratio of 3,4-dihydroxyphenylacetic acid-to-dopamine remained unchanged in comparison with that of the pretreatment levels. Whereas no change in the striatal 5-hydroxyindoleacetic acid concentrations was seen with the lowest and highest dose regimen, the intermediate dose elicited a moderate increase (20%) in basal 5-hydroxyindoleacetic acid levels. The pharmacological relevance of the effects of tamoxifen on the dopaminergic and 5-HTergic systems, as a prelude to the development of non-steroidal oestrogenic compounds in reducing the risk of neurodegenerative disorders such as Alzheimer's disease, is discussed.

Tonsillectomy and the value of peritonsillar infiltrations

In this prospective double-blind trial, the effect of peritonsillar infiltrations was assessed with regard to intra-operative bleeding and postoperative pain in 100 young adults who underwent elective tonsillectomy under balanced general anaesthesia. Patients were randomly assigned to 1 of 5 groups (20 patients in each group) and received infiltrations as follows: group 1--bupivacaine (0.5%) with adrenaline (1:200,000); group II--bupivacaine (0.5%); group III--normal saline with adrenaline (1:200,000); group IV--normal saline; group V--no infiltration (control group). With regard to blood loss, groups I-IV lost a mean of 47 ml (95% CI = 69.78), while group V lost a mean of 121 ml (95% CI = 78.10) (P = 0.0002). Group V had the highest pain score (average 4.62) measured in recovery, 4 and 24 hours after tonsillectomy (P = 0.0051) and required more narcotic analgesia. Groups II and III had the lowest score (average 1.72) after 24 hours. The bupivacaine group (II) had the highest incidence (71.4%) of nausea and vomiting. Peritonsillar infiltrations decrease intra-operative bleeding and pain, independent of the type of solution infiltrated, by providing a better defined plane of dissection which minimises trauma to the surrounding tissue. Normal saline infiltrations with or without adrenaline should be used since they have no side-effects and are inexpensive and easily available.

Recommended guidelines for the treatment of chemotherapy-induced diarrhea

PURPOSE

Management of chemotherapy-induced diarrhea (CID) has customarily involved symptomatic treatment with opioids in conjunction with supportive care. Alternatively, patients refractory to conventional therapy have been given octreotide, a somatostatin analogue. Although this agent has been effective against CID, no widely accepted treatment guidelines that incorporate its use currently exist. An expert multidisciplinary panel was convened to formulate clinical practice guidelines for the treatment of CID.

METHODS

The panel reviewed clinical data on the management of CID reported in the literature and analyzed currently available tools used to assess CID. Expert consensus was applied when published data were insufficient. Panel members also considered the effect of CID on quality of life and the cost-effectiveness and efficacy of different pharmacologic approaches. Effective resolution of CID and decreases in the need for supportive care or hospitalization were considered to be primary goals in the formulation of the guidelines.

RESULTS

The panel formulated suggested practice guidelines for the management of CID that detail recommendations for the assessment and evaluation of diarrhea and the sequence and duration of administration of specific pharmacologic agents.

CONCLUSION

The consensus of the panel was that standardized assessment and management of diarrhea is required to effectively control CID. The panel agreed that further data from a National Cancer Institute (NCI)-sponsored intergroup trial is required to determine the optimal dosage of octreotide and its cost in the treatment of cancer. The panel also agreed that further clinical research is warranted to address significant questions about the most effective way to assess and treat CID.

Diagnosis of renal artery stenosis and renovascular hypertension

Renovascular hypertension resulting from renal artery stenosis is a potentially curable form of secondary hypertension. Although uncommon in the general hypertensive population, the prevalence of renovascular hypertension rises in selected groups of hypertensive patients. Because of the possibility of cure, screening measures for renal artery stenosis are warranted in hypertensive patients with clinical features suggestive of renovascular disease. For a long time, angiography has been considered the 'gold standard' in screening for arterial stenosis. However, it is invasive and associated with inherent morbidity. Thus, less invasive screening measures with high diagnostic sensitivity and specificity are currently being sought. Magnetic resonance angiography and captopril renal scintigraphy are safer alternatives to angiography, but are expensive and not widely available. Duplex ultrasound is more widely available and provides both anatomic and functional assessment of renal artery stenosis; however, sensitivity and specificity vary considerably among different laboratories. Echo-enhanced duplex ultrasound using the galactose-based agent Levovist(R) produces higher quality images of the renal artery than conventional color Doppler, while significantly reducing mean examination time and improving diagnostic confidence. In addition, Levovist does not compromise the safety of duplex ultrasound. Other advances in Doppler imaging techniques that may improve ultrasound sensitivity and specificity in detection of renal artery stenosis are power Doppler, echo-enhanced harmonic spectral Doppler imaging, and echo-enhanced harmonic power Doppler imaging.

Medium-term effects of a new 5HT3 antagonist, alosetron, in patients with carcinoid diarrhoea

BACKGROUND

Carcinoid diarrhoea is associated with rapid small bowel and proximal colonic transit. Intravenous administration of a serotonin type 3 receptor (5HT3) antagonist restores postprandial colonic tone towards normal in carcinoid patients.

AIMS

To evaluate the medium-term effects of an oral 5HT3 antagonist, alosetron, on symptoms, stool fat, and transit in patients with carcinoid diarrhoea.

METHODS

In 27 patients with carcinoid diarrhoea, symptoms were recorded daily and gastrointestinal transit was measured by scintigraphy in a three dose (0.1, 0.5, 2.0 mg, twice daily), randomised (1:1:1), parallel group, four week study. Placebo was given during the first week. Loperamide (2 mg capsules) was used as rescue medication.

RESULTS

There were numerical improvements in median diarrhoea score, stool weight, loperamide use, and overall colonic transit at four hours, but no overall significant drug effect was shown. Alosetron reduced the proximal colon emptying rate (p < 0.05 in 20 evaluable comparisons), but did not significantly alter small bowel transit.

CONCLUSIONS

Alosetron retardation of proximal colonic emptying in patients with carcinoid diarrhoea confirms the potential role of a 5HT3 mechanism in this disorder. Doses of alosetron higher than 2.0 mg twice daily will be required for symptomatic benefit in carcinoid diarrhoea.

Dexamethasone promotes expression of membrane-bound macrophage colony-stimulating factor in murine osteoblast-like cells

The mechanisms by which glucocorticosteroids promote osteoclastogenesis in vitro are uncertain. As macrophage colony-stimulating factor (MCSF) is critical for osteoclastogenesis, we hypothesized that glucocorticosteroids might regulate membrane-bound MCSF (mMCSF) and soluble MCSF (sMCSF) production by stromal cells or osteoblasts. ST2 cells or murine calvarial osteoblasts (MOBs) were treated with dexamethasone (Dex; 100 nM) and/or 1,25-dihydroxyvitamin D [1,25(OH)2D; 10 nM] for 3 days. Control values for mMCSF and sMCSF as units per 100,000 cells were 9 +/- 1.4 and 511 +/- 56 in ST2 cells and 5.9 +/- 0.8 and 379 +/- 47 in MOB cells, respectively. Dex increased mMCSF to 156 +/- 16% and 143 +/- 26% compared with the control value in ST2 and MOB cells, respectively, whereas 1,25-(OH)2D caused increases of 195 +/- 16% and 164 +/- 21%. In the presence of both Dex and 1,25-(OH)2D, mMCSF increased to 209 +/- 24% and 216 +/- 26% in the two cell types, respectively. 1,25-(OH)2D caused modest increases in sMCSF, as expected, in both cell types (153 +/- 6% and 122 +/- 4%). Dex inhibited 1,25-(OH)2D-stimulated sMCSF (115 +/- 7% of control) in ST2 cells. Analysis of mMCSF transcript levels by semiquantitative RT-PCR revealed Dex-stimulated increases of 170 +/- 11% in ST2 cells and 126 +/- 16% in MOB cells compared with the control level. The increased expression of the transcript for sMCSF in the presence of Dex and 1,25-(OH)2D, measured by both RT-PCR and Northern analysis (219 +/- 53% and 242%, respectively), despite inhibition of sMCSF protein, indicated that the inhibitory effect of Dex in ST2 cells was posttranscriptional. Half-life studies showed that Dex prolonged MCSF messenger RNA from 2.8 to 7.5 h. These results suggest that Dex influences osteoclastogenesis by increasing the expression of mMCSF by accessory cells in culture.