Serum prolactin in human immunodeficiency virus infection

Patients infected with human immunodeficiency virus (HIV) have higher serum prolactin compared to healthy controls but this is controversial. As part of a laboratory audit investigating the interference of macroprolactin in our prolactin assay, we investigated whether low biological activity macroprolactin could account for the increased serum prolactin concentrations observed in HIV infection. We, therefore, compared serum total prolactin and free prolactin in 32 subjects infected with HIV (HIV+ve) with 52 subjects not infected with HIV (HIV-ve). Serum total prolactin concentrations were similar in HIV+ve and HIV-ve patients [median (95% confidence limits); 167.0 (122.4 - 313.8) vs 206.5 (187.8 - 248.4) mU/L respectively]. Serum free prolactin concentrations were lower (p <0.005) in HIV+ve subjects than in HIV-ve subjects [112.0 (91.1-141.8) vs 171.0 (154.5 - 200.9) mU/L respectively; p<0.0005]. These results are consistent with the notion that low biological activity macroprolactin contributes to circulating prolactin concentrations in HIV+ve subjects.

An investigation of nitric oxide metabolites during symptomatic myocardial ischaemia in relation to exercise tolerance test

BACKGROUND

Nitric oxide (NO) plays a pivotal role in the pathophysiology of coronary heart disease (CHD). Low plasma concentrations of NO metabolites (nitrite and nitrate), the stable oxidation products of NO have been reported in patients with CHD but this is controversial. Plasma nitrite and nitrate concentrations during symptomatic myocardial ischaemia and in response to exercise in subjects with CHD have not been studied. We therefore measured plasma nitrite and nitrate concentrations in subjects before and after an exercise tolerance test (ETT).

MATERIAL/METHODS

Plasma nitrite and nitrate concentrations were measured before and after an ETT in 24 subjects with symptomatic exercise-induced myocardial ischaemia (positive ETT) and in 27 subjects without exercise-induced myocardial ischaemia (negative ETT).

RESULTS

Plasma nitrate concentrations were higher (p<0.002) before and after the ETT in subjects with a positive ETT (31.51+/-21.80 mol/L and 30.86+/-21.42 mol/L respectively) than in the subjects with a negative ETT (14.75+/-6.71 mol/L and 15.64+/-6.50 mol/L respectively). Plasma nitrite concentrations before and after the ETT were similar in both groups. Within each group, plasma nitrite and nitrate concentrations were not altered by exercise.

CONCLUSIONS

Subjects with exercise-induced myocardial ischaemia have higher plasma nitrate concentration than subjects without exercise-induced myocardial ischaemia. This is consistent with either a compensatory or an inflammatory response of the vascular endothelium to endothelial damage. Symptomatic exercise-induced ischaemia is not associated with altered plasma NO metabolite concentrations.

Effect of a protease inhibitor on in vitro stability of intact parathyroid hormone

BACKGROUND

We investigated whether increased protease activity explains the increased in vitro degradation of intact parathyroid hormone (iPTH) observed in serum when compared to EDTA plasma.

METHODS

Pre-dialysis blood samples for iPTH were taken from 11 patients with chronic renal failure and collected into plain glass tubes, tubes containing 200 KIU/mL aprotinin (a protease inhibitor) and EDTA tubes. All sample aliquots were separated at 20 min, 1 h, 2 h, 4 h, 8 h and 24 h post collection.

RESULTS

Over 24 h, iPTH concentrations remained unchanged in EDTA tubes. iPTH concentrations were significantly lower in both plain tubes (P < 0.01) and aprotinin tubes (P < 0.001) at 24 h when compared to the baseline sample (20 min). At 24 h, iPTH concentrations in EDTA tubes were higher than in plain tubes (P < 0.001) and aprotinin tubes (P < 0.01). The addition of aprotinin to plain tubes significantly reduced the degradation of iPTH (P < 0.05) at 24 h.

CONCLUSION

Aprotinin significantly reduces the in vitro degradation of iPTH in plain tubes at 24 h from 24.7% to 9.6%. We suggest that increased protease activity contributes to the decline in serum iPTH over time. As this is observed in serum and not plasma it suggests that the increased protease activity may be due to the clotting process.

Ethnic differences in total and HDL cholesterol concentrations: Caucasians compared with predominantly Punjabi Sikh Indo-Asians

BACKGROUND

In comparison with Caucasians, Indo-Asians resident in the UK have similar total cholesterol but lower HDL cholesterol (HDLC) concentrations. It is however possible that cardiovascular risk factors may vary between culturally different Indo-Asians.

METHODS

We present data on 223 Indo-Asians (129 men, 94 women) and 787 Caucasians (421 men, 366 women) in whom a laboratory-based coronary heart disease (CHD) risk score calculation had been requested.

RESULTS

Total cholesterol concentrations were similar in Indo-Asians and Caucasians. HDLC concentrations were higher (P < 0.001) in Caucasians [1.4 (1.3-1.4) mmol/L; median (95% confidence intervals)] than in Indo-Asians [1.2 (1.2-1.3) mmol/L]. Indo-Asian women [1.2 (1.2-1.3) mmol/L], Indo-Asian men [1.2 (1.2-1.3) mmol/L] and Caucasian men [1.2 (1.2-1.3) mmol/L] had similar HDLC concentrations but these were all lower (P < 0.001) than those in Caucasian women [1.4 (1.3-1.4) mmol/L].

CONCLUSION

We confirm low HDLC concentrations in Indo-Asians, but propose that this is solely due to low HDLC concentrations in Indo-Asian women. Since Indo-Asians in Wolverhampton are predominantly Punjabi Sikhs, we suggest that the difference between this study and previous reports may be due to heterogeneity of CHD risk factors within culturally diverse Indo-Asians.

Urine microalbumin excretion in relation to exercise-induced electrocardiographic myocardial ischaemia

BACKGROUND

Microalbuminuria, a marker of endothelial cell dysfunction, is associated with atherosclerosis and is a predictor of coronary heart disease. It has been suggested that patients with coronary heart disease have exaggerated exercise-induced urinary microalbumin excretion but this is controversial. We, therefore, measured urine microalbumin excretion in men before and after an exercise electrocardiogram.

MATERIAL/METHODS

Urine microalbumin excretion expressed as the albumin-creatinine ratio (ACR) was measured before and after an exercise electrocardiogram in 10 subjects with exercise-induced myocardial ischaemia and 14 subjects without exercise-induced myocardial ischaemia.

RESULTS

In subjects with a positive exercise electrocardiogram, the pre-exercise electrocardiogram ACR 3.3 +/- 5.50; (mean+/-SD) significantly increased (p=0.0371) following exercise (6.30 +/-10.25). In subjects with a negative exercise electrocardiogram, the pre-exercise electrocardiogram ACR (0.73 +/-0.52) also significantly increased (p=0.0295) following exercise (2.04 +/-1.81). Pre-exercise ACR was higher (p=0.0164) in subjects with a positive exercise electrocardiogram (3.3 +/-5.50) than in those subjects with a negative exercise electrocardiogram (0.73 +/-0.52). Incremental and post-exercise ACR were not significantly different in those with normal and abnormal exercise electrocardiograms.

CONCLUSIONS

Patients with exercise-induced myocardial ischaemia have pre-exercise urine microalbumin excretion. Exaggerated urine microalbumin excretion in response to exercise is not associated with exercise-induced myocardial ischaemia.

Ethnic variation in C-reactive protein: UK resident Indo-Asians compared with Caucasians

BACKGROUND

The increased prevalence of coronary heart disease (CHD) in UK resident Indo-Asians is unexplained by the traditional cardiovascular risk factors of dyslipidaemia, hypertension, smoking and diabetes mellitus. C-reactive protein (CRP) has been implicated in the pathogenesis of CHD but the data on ethnic variation in CRP is conflicting. We therefore investigated whether CRP could help explain the increased prevalence of CHD in Indo-Asians.

DESIGN AND METHODS

We measured CRP, using a highly sensitive assay, in 102 men (63 Caucasians and 39 Indo-Asians) and 89 women (58 Caucasians and 31 Indo-Asians). All subjects, aged between 40 and 70 years, were nondiabetic and nonsmokers.

RESULTS

Serum CRP correlated (P < 0.05) positively with coronary risk. Serum HDL cholesterol concentrations were lower (P<0.05) in Indo-Asian women when compared with Caucasian women, but otherwise the ethnic groups were matched for calculated coronary risk and cardiovascular risk factors. Serum CRP concentrations were similar in Indo-Asians (women 2.29 (1.52) mg/l [mean (SD)]; men 1.77 (1.46) mg/l) and Caucasians (women 2.23 (1.54) mg/l; men 1.94 (1.45) mg/l).

CONCLUSIONS

Altered CRP concentrations does not appear to be implicated in the increased prevalence of CHD in UK resident Indo-Asians.

Comparative evaluation of the new Sheffield table and the modified joint British societies coronary risk prediction chart against a laboratory based risk score calculation

BACKGROUND

Management of borderline hypertension and hypercholesterolaemia is based on an individual's coronary heart disease (CHD) risk rather than arbitrary values for blood pressure or serum cholesterol. Prediction of CHD risk involves using tables, charts, or computer programs based on the Framingham equations. The new Sheffield table and modified joint British societies coronary risk prediction (JBS) chart are widely used. The JBS chart approximates age and systolic blood pressure, and the new Sheffield table dichotomises blood pressure, and these simplifications may lead to diagnostic inaccuracy.

METHODS

The diagnostic performance of the charts against an individualised laboratory based CHD risk calculation in 1102 subjects in primary care were evaluated and compared.

RESULTS

The new Sheffield table and modified JBS chart performed equally well with a respective diagnostic sensitivity and specificity of 91.6% (95% confidence interval 86.7% to 95.1%) and 93.8% (91.1% to 97.9%), and 93.6% (90.4% to 96.0%) and 94.7% (92.6% to 96.1%) at 10 year CHD risk of 15%; and of 95.2% (82.8% to 99.4%) and 97.9% (96.8% to 98.7%), and 90.5% (75.6% to 97.4%) and 100% (99.7% to 100%) at 10 year CHD risk of 30%. The modified JBS chart graphic display provides graded risk, which may be an advantage over the new Sheffield table, which identifies thresholds of risk. The new Sheffield table, unlike any other method, can be used as screening tool for cholesterol measurement.

CONCLUSIONS

The new Sheffield table and modified JBS chart are valid for use in primary care since their diagnostic accuracy is unaffected by approximations in age and blood pressure. It is suggested that practitioners should choose whichever risk assessment tool they are comfortable with and use it.

Herbal remedy poisoning presenting with acute abdomen and raised urine porphyrins

We describe a case of lead poisoning due to herbal remedies, presenting with an acute abdomen, raised porphyrins and increased liver enzyme activities. We suggest that lead poisoning should be considered in the differential diagnosis of the 'acute abdomen', and that the presence of liver dysfunction points to the possibility of Asian herbal remedies as the source of the lead poisoning.

'Glucose meter hypoglycaemia': often a non-disease

The diagnosis of hypoglycaemia depends upon the demonstration of a low blood glucose concentration during a spontaneous symptomatic episode. Glucose monitoring devices may misdiagnose many healthy individuals with nonspecific symptoms as having hypoglycaemia. We present three illustrative cases of 'glucose meter non-hypoglycaemia'.

Combined paclitaxel, cisplatin, and etoposide for patients with previously untreated esophageal and gastroesophageal carcinomas

BACKGROUND

Paclitaxel (T), etoposide (E), and cisplatin (P) are each active in gastric carcinoma, either as single agents or as part of a multidrug regimen. To the authors' knowledge, the combination of these three agents in the treatment of patients with esophageal or gastroesophageal carcinoma has not been previously studied.

METHODS

Previously untreated patients with locally advanced carcinoma of the stomach, esophagus, or gastroesophageal (GE) junction received at least 2 cycles of TPE administered twice weekly for 3 weeks, with the cycle repeated every 28 days. Drug doses, administered over 3 hours on either Monday and Thursday or Tuesday and Friday, consisted of T 50 mg/m2/dose, P 15 mg/m2/dose, and E 40 mg/m2/dose. For patients with local disease only, subsequent therapy consisted of radiation with or without surgical resection.

RESULTS

Twenty-five patients with gastric (10) or gastroesophageal or GE junction (15) carcinoma were treated. Eighteen had locally advanced disease and 7 had liver metastases at presentation. Hematologic toxicity, namely, Grade 3 anemia and neutropenia, was experienced by all patients. The median number of treatment cycles was 4 (range, 2-6). Three patients were not evaluable for response. All 22 evaluable patients responded; 3 were complete responders and 19 were partial responders. Eleven patients received radiation therapy with (6) or without (5) concomitant 5-fluorouracil, and 8 patients subsequently underwent surgical resection. Three of 8 patients had no tumor at surgery, 4 had minimal microscopic tumor at the primary site, and 3 had microscopic lymph node involvement. Twenty-three patients are alive, of whom 14 are without evidence of disease. Two patients with metastatic disease at presentation died at 9 and 29 months, respectively. The median survival was 12.5 months (range, 6 to 30+ months).

CONCLUSIONS

Multifractionated TPE chemotherapy is a highly active regimen in gastric and gastroesophageal carcinoma. It could be evaluated in Phase III trials against other active regimens for the treatment of patients with this disease. The introduction of 5-fluorouracil could also be an interesting direction to explore because of its primary role in the treatment of patients with gastric and esophageal carcinoma.

Comparison of costs for infusion versus bolus chemotherapy administration--Part two. Use of charges versus reimbursement for cost basis

BACKGROUND

The costs of infusion versus bolus administration of chemotherapy has been a point of controversy as has been the method of quantitating the cost. The present study analyzes the reimbursement for chemotherapy administration by infusion compared with bolus delivery based on reimbursement and relates this to cost based on projected charges and actual charges in a private practice setting.

METHODS

Actual reimbursement records were retrieved for selected patients receiving infusion or bolus administration of specific chemotherapy regimens for three tumors: colon carcinoma, breast carcinoma, and lymphoma. All services were included except for radiology and hospitalization. Medicare reimbursement represented 90% of the treatment cycles analyzed.

RESULTS

Actual reimbursement per month for each infusion regimen was as follows: colon carcinoma, $528 (5-fluorouracil [5-FU]); breast carcinoma, $621 (doxorubicin and cyclophosphamide [AC]) and $685 (cyclophosphamide, methotrexate, and fluorouracil [CMF]); and lymphoma, $603 (cyclophosphamide, doxorubicin, vincristine, and prednisone [CHOP]). Actual reimbursement per month for a bolus regimen was colon carcinoma, $393 (5-FU + leucovorin); breast carcinoma, $991 (AC) or $453 (CMF); and lymphoma, $749 (CHOP). Actual reimbursement represents 21-36% of actual charges. Projected charges based on the model system are generally less than the actual charges.

CONCLUSIONS

The cost of chemotherapy as defined by reimbursement are substantially less than actual charges and are also less than projected costs based on charges. Data comparing bolus versus infusion reimbursement costs for colon carcinoma, breast carcinoma, and lymphoma indicate that differences between reimbursement for bolus and infusion administration are not substantial.

Comparison of costs for infusion versus bolus chemotherapy administration: analysis of five standard chemotherapy regimens in three common tumors--Part one. Model projections for cost based on charges

BACKGROUND

The cost of infusional administration of cancer chemotherapy has been assumed to be more expensive than the traditional bolus schedule related to the use of durable medical equipment and other components of the delivery system. The objective was to develop a model of projected charges as a basis for the cost estimate for selected common chemotherapy regimens comparing the cost based on charges for bolus and infusional chemotherapy schedules.

METHODS

Chemotherapy programs using either bolus or infusional delivery were selected representing standard or commonplace regimens for the treatment of patients with breast cancer (cyclophosphamide, methotrexate, fluorouracil [CMF] or CA); colon cancer (5-fluorouracil[5-FU] infusion vs. 5-FU bolus + leucovorin [LCVI] or lymphoma (cyclophosphamide, hydroxydaunomycin, Oncovin (vincristine), prednisone [CHOP] or CDE [cyclophosphamide, doxorubicin, etoposide]). Cost projections were estimated based on charges and were calculated in a model system using six charge (cost) centers including medical doctor [MD] and/or clinic visit; laboratory; drug cost based on average wholesale price (AWP); cost of disposables; and pump rental fee. Standard dosages were applied for each regimen using total mg/M2 for a 1.5 M2 person.

RESULTS

Projected charges or chemotherapy for colon cancer (5-FU infusion vs. 5-FU + LCV) are variable depending on the LCV dose and the infusion duration. The longer infusion duration or higher doses of LCV result in a 40 to 50% increment in monthly charges excluding cost related to toxicity. For breast cancer, the charges for bolus or infusion administration CMF are similar, but for CA bolus charges are higher than infusion charges related to higher drug doses. For lymphoma, CHOP chemotherapy dosage costs are approximately half of those for CDE infusion related to the specific drug regimen and drug dosage used.

CONCLUSIONS

The perception that infusional delivery of chemotherapeutic agents adds to the cost of cancer care is appropriate for some regimens but the absolute amount of cost increment is generally modest. The principle cost differences between bolus and infusional schedules relate to drug dosage and the toxicity profile. Generally, but not consistently, infusional schedules use lesser doses and are associated with lesser toxicity. Although the benefit of infusional delivery of chemotherapy in terms of response rates and survival are comparable to bolus schedules for 5-FU infusion and 5-FU + LCV in colon cancer, this has not been established for the regimens analyzed for breast cancer (CMF, CA) or lymphoma (CDE, CHOP). The misperception of cost advantages for bolus delivery should not preclude comparative trials of bolus versus infusional chemotherapy schedules and cost should be studied prospectively in clinical trials comparing different schedules of administration in addition to studies of quality of life and toxicity.

Pilot study of ambulatory infusional ifosfamide admixed with carboplatin

BACKGROUND

Ifosfamide and carboplatin are agents that have completed Phase I studies using a continuous infusion schedule for as long as 14 days. The in vitro compatibility of the two drugs allows for the simultaneous administration in an admixture, and a pilot study was undertaken to determine the feasibility and tolerability of the infusion schedule for the combination.

METHODS

Ifosfamide at 500 mg/M2/day and carboplatin at 15 or 20 mg/M2/day were administered for 14-day cycles repeated at 28 days in 29 patients, with a total of 60 courses administered.

RESULTS

Total cumulative dose per cycle was: ifosfamide 7.0 g/M2 and carboplatin 210-280 mg/M2. Hematuria developed in five patients, four of whom had prior urologic disease, severe thrombocytopenia, or pelvic radiation. In all patients, the hematuria was transient and inconsequential despite the absence of mesna. Grade 3 or 4 leukopenia was observed in eight patients with or without thrombocytopenia and delayed subsequent treatment cycles. Thrombocytopenia was less frequent (Grade 3, 2 patients: Grade 4, 1 patient). No significant episodes of sepsis or hemorrhage were noted. Anemia requiring transfusion developed in 12 of 29 patients. Twenty-one of the 29 patients had received prior chemotherapy. Five of seven previously untreated patients with non-small cell lung cancer achieved a complete (1) or partial (4) response.

CONCLUSIONS

A continuous 14-day infusion of ifosfamide admixed with carboplatin is feasible in an ambulatory setting with no need for adding mesna for urologic protection and full dosage administration for each agent. Phase 2 studies in non-small cell lung cancer would be reasonable at the optimal doses of ifosfamide 500 mg/M2/day and carboplatin 15 mg/M2/day, and the potential exists for the introduction of additional agents, such as etoposide.

Ifosfamide extrapyramidal neurotoxicity

Ifosfamide-associated central nervous system toxicity has been reported in 5% to 30% of patients treated with ifosfamide. Its pattern is characterized by metabolic encephalopathy with confusion, blurred vision, mutism, auditory or visual paranoid hallucinations, seizures, and rarely coma. The biochemical cause of the neurotoxicity is not understood completely, but it is thought to result from an accumulation of drug metabolites with direct central nervous system effects. A case of ifosfamide neurotoxicity is reported that had unusual extrapyramidal features in a patient treated with a 5-day course of infused ifosfamide. Although usually spontaneously reversible with cessation of drug administration, ifosfamide neurotoxicity occasionally has been associated with prolonged psychopathologic sequelae. Death from irreversible encephalopathy has also been reported rarely. The authors believe that classic extrapyramidal symptoms should be considered to be a part of the neurotoxic profile of ifosfamide.

Etoposide in combination with cytarabine, doxorubicin, and 6-thioguanine for treatment of acute nonlymphoblastic leukemia in a protocol adjusted for age

Etoposide combined with cytarabine, doxorubicin, and 6-thioguanine was used to treat 34 patients with acute nonlymphoblastic leukemia (ANLL) in an age-adjusted protocol, with patients greater than 50 years old receiving fewer days of therapy. Complete remissions (CR) occurred in 85% of all patients (29 of 34 patients). Patients less than or equal to 50 years of age achieved a 94% CR rate (17 of 18 patients) compared to a 75% CR rate (12 of 16 patients) in older patients. Duration of remission was less for those greater than 50 years of age. The remission rate for primary ANLL was 86% (19 of 22 patients) and for secondary or relapsed ANLL was 83% (ten of 12 patients). Thus, this is effective therapy for primary and secondary or relapsed ANLL. When the days of therapy are reduced for older patients' age, the remissions are fewer and less durable.