For which functions are 𝑓(𝑋_{𝑡})-𝔼𝕗(𝕏_{𝕥}) and 𝕘(𝕏_{𝕥})/𝔼𝕘(𝕏_{𝕥}) martingales?

Let X = ( X t ) t ≥ 0 X=(X_t)_{t\geq 0} be a one-dimensional Lévy process such that each X t X_t has a C b 1 C^1_b -density w. r. t. Lebesgue measure and certain polynomial or exponential moments. We characterize all polynomially bounded functions f : R → R f\colon \mathbb {R}\to \mathbb {R} , and exponentially bounded functions g : R → ( 0 , ∞ ) g\colon \mathbb {R}\to (0,\infty ) , such that f ( X t ) − E f ( X t ) f(X_t)-\mathbb {E} f(X_t) , resp. g ( X t ) / E g ( X t ) g(X_t)/\mathbb {E} g(X_t) , are martingales.

PRO B: evaluating the effect of an alarm-based patient-reported outcome monitoring compared with usual care in metastatic breast cancer patients-study protocol for a randomised controlled trial

Background

Despite the progress of research and treatment for breast cancer, still up to 30% of the patients afflicted will develop distant disease. Elongation of survival and maintaining the quality of life (QoL) become pivotal issues guiding the treatment decisions. One possible approach to optimise survival and QoL is the use of patient-reported outcomes (PROs) to timely identify acute disease-related burden. We present the protocol of a trial that investigates the effect of real-time PRO data captured with electronic mobile devices on QoL in female breast cancer patients with metastatic disease.

Methods

This study is a randomised, controlled trial with 1:1 randomisation between two arms. A total of 1000 patients will be recruited in 40 selected breast cancer centres. Patients in the intervention arm receive a weekly request via an app to complete the PRO survey. Symptoms will be assessed by study-specific optimised short forms based on the EORTC QLQ-C30 domains using items from the EORTC CAT item banks. In case of deteriorating PRO scores, an alarm is sent to the treating study centre as well as to the PRO B study office. Following the alarm, the treating breast cancer centre is required to contact the patient to inquire about the reported symptoms and to intervene, if necessary. The intervention is not specified and depends on the clinical need determined by the treating physician. Patients in the control arm are prompted by the app every 3 months to participate in the PRO survey, but their response will not trigger an alarm. The primary outcome is the fatigue level 6 months after enrolment. Secondary endpoints include among others hospitalisations, use of rescue services and overall QoL.

Discussion

Within the PRO B intervention group, we expect lower fatigue levels 6 months after intervention start, higher levels of QoL, less unplanned hospitalisations and less emergency room visits compared to controls. In case of positive results, our approach would allow a fast and easy transfer into clinical practice due to the use of the already nationwide existing IT infrastructure of the German Cancer Society and the independent certification institute OnkoZert.

Trial registration

DRKS (German Clinical Trials Register) DRKS00024015. Registered on 15 February 2021

Supplementary Information

The online version contains supplementary material available at 10.1186/s13063-021-05642-6.

Training courses on hereditary breast and ovarian cancer to strengthen cross-sectoral care in underserved areas

OBJECTIVE

To strengthen cross-sectoral care by disseminating specialized knowledge about hereditary breast and ovarian cancer across underserved areas.

METHODS

We report on a training course about genetic counseling and testing of hereditary breast and ovarian cancer patients for gynecologists from certified cancer centers. In total, 50 gynecologists attended the course which was offered once annually between 2017 and 2019. Before and after the course, participants were asked to answer a self-assessment questionnaire and completed the training with a multiple-choice test. The results of the self-assessments and knowledge tests were analyzed to steadily improve the training.

RESULTS

The self-assessments imply a perceived increase in certainty regarding the inclusion criteria for specialized genetic counseling, pedigree analysis, and contents of the initial consultation. Both the knowledge tests and self-assessments showed that participants had difficulties in interpreting and differentiating between age-specific and lifetime risks.

CONCLUSION

The courses successfully conveyed knowledge necessary to identify patients at risk and to provide timely genetic analyses even in rural areas.

PRACTICE IMPLICATIONS

The results are a promising basis for creating additional training courses addressing specialists in hospitals and gynecological practices. Further education of physicians might improve cross-sectoral cooperation and thereby enable specialized care supply in rural areas.

Measuring Quality of Life Using Patient-Reported Outcomes in Real-World Metastatic Breast Cancer Patients: The Need for a Standardized Approach

Simple Summary

Metastatic breast cancer (MBC) remains incurable despite treatment improvements. The health-related quality of life is a multidimensional entity which covers physical, psychological and social dimensions. It is an important outcome particularly in patients with metastatic disease, as the primary goal of therapy is no longer curation, but to provide the best possible quality of life weighted against treatment risks and adverse symptoms. Patient-reported outcomes reflecting the quality of life are usually measured with validated questionnaires to evaluate treatment strategies based on symptom burden and to improve care delivery. This review shares insights into the role of patient-reported outcome measurements in MBC patients and describes the heterogeneity of current questionnaires. We conclude that an up-to-date and standardized outcome set is needed, containing relevant domains referring to individual needs to improve the quality of life assessment among MBC patients. This is a prerequisite to learn about how they could impact the clinical care pathway.

Abstract

Metastatic breast cancer (MBC) patients are almost always treated to minimize the symptom burden, and to prolong life without a curative intent. Although the prognosis of MBC patients has improved in recent years, the median survival after diagnosis is still only 3 years. Therefore, the health-related quality of life (HRQoL) should play a leading role in making treatment decisions. Heterogeneity in questionnaires used to evaluate the HRQoL in MBC patients complicates the interpretability and comparability of patient-reported outcomes (PROs) globally. In this review, we aimed to provide an overview of PRO instruments used in real-world MBC patients and to discuss important issues in measuring HRQoL. Routinely collecting symptom information using PROs could enhance treatment evaluation and shared decision-making. Standardizing these measures might help to improve the implementation of PROs, and facilitates collecting and sharing data to establish valid comparisons in research. This is a prerequisite to learn about how they could impact the clinical care pathway. In addition, the prognostic value of intensified PRO collection throughout therapy on survival and disease progression is promising. Future perspectives in the field of PROs and MBC are described.

A German Study Comparing Standard Wire Localization With Magnetic Seed Localization of Non-palpable Breast Lesions

BACKGROUND

Exact localization of non-palpable breast lesions is necessary to ensure that the correct lesion is removed. Conventional methods come with several disadvantages.

PATIENTS AND METHODS

We compared 28 patients who underwent breast-conserving surgery for a non-palpable lesion. By surgeon choice, 14 patients were assigned to undergo magnetic seed localization and 14 underwent standard wire localization. The primary outcome was the operative time, and secondary outcome was the patient pain level.

RESULTS

The mean age was 52±10 (SD) years in the seed arm, and 55±13 years in the wire arm. The median time from skin incision to tumor extraction was not significantly different between the two groups. Patients in the wire localized group significantly more often reported pain during coughing/breathing, movement, and sleep.

CONCLUSION

Using seed localization at Charité Breast Center did not lead to a significant decrease in operative time but might allow time savings once established, while increasing patient comfort and reducing organizational burden.

A Pilot Study Evaluating the Effects of Magtrace® for Sentinel Node Biopsy in Breast Cancer Patients Regarding Care Process Optimization, Reimbursement, Surgical Time, and Patient Comfort Compared With Standard Technetium99

Background

Sentinel lymph node biopsy after technetium-99 (Tc⁹⁹) localization is a mainstay of oncologic breast surgery. The timing of Tc⁹⁹ injection can complicate operating room schedules, which can cause increasing overall costs of care and patient discomfort.

Methods

This study compared 59 patients who underwent breast cancer surgery including sentinel lymph node biopsy. Based on the surgeon’s choice, 29 patients were treated with Tc⁹⁹, and 30 patients received the iron-based tracer, Magtrace. The primary outcomes were time spent on the care pathway and operating time from commissioning of the probe to removal of the sentinel node. The secondary outcomes were patient pain levels and reimbursement.

Results

The mean time spent on the preoperative breast cancer care pathway was significantly shorter for the Magtrace group (5.4 ± 1.3 min) than for the Tc⁹⁹ group (82 ± 20 min) (p < 0.0001). The median time from probe usage to sentinel node extirpation was slightly but not significantly shorter in the Magtrace group (5 min; interquartile range [IQR], 3–15 min vs 10 min; IQR, 7–15 min; p = 0.151). Reimbursement and pain levels remained unchanged, and the hospital length of stay was similar in the two groups (Magtrace: 5.1 ± 2.3 days vs Tc⁹⁹: 4.5 ± 3.2 days).

Conclusions

Magtrace localization shortened the preoperative care pathway and did not affect surgical time or reimbursement. Once established, it could allow for cost reduction and improve patient comfort.

Intraoperative indocyanine green fluorescence imaging in breast surgery

Background

Since postoperative complications after reconstructive breast surgery are often related to drastic increases of patient suffering and treatment costs, several devices were developed in order to avoid them. In this respect, the intraoperative fluorescence angiography with indocyanine green (ICG) provides promising results by detecting ischemic skin intraoperatively.

Methods

Women who underwent reconstructive breast surgery at the breast center at Charité between April and December 2017 were included in the analysis. General patient characteristics, medical history, type of surgery, as well as postoperative parameters, complications and patient reported outcomes were compared between patients operated using ICG fluorescence angiography and conventionally operated patients.

Results

Among 68 patients with breast reconstruction 36 (52.9%) were operated with the ICG angiography device and 32 (47.1%) without. No significant differences regarding patient demographics, medical history, and surgical procedure were found. Wound healing disorders occurred in 11.1% of the ICG group and in 9.4% of the control group. About 11% of both groups developed major complications which required revision surgery. Complication rates and patient reported outcome did not differ significantly. Across both groups, only the risk factor resection weight (≥ 500 g) was significantly associated with wound healing disorders (RR = 6.80; 95%CI 1.93–23.81; p = 0.022).

Conclusion

The purchase of a device for intraoperative ICG angiography might not be reasonable for every breast center. Further research in a larger cohort and prospective manner should be done to determine if the addition of ICG to breast reconstructive surgery in the German setting really leads to improved patient care.

[Treatment of a subsequently detected, iatrogenic colonic perforation via minimal-invasive rendezvous procedure]

Laparoscopic surgery as primary therapeutical option for iatrogenic colonic perforation after colonoscopy can be complemented by intraoparative colonoscopy in order to detect and treat even difficult accessible lesions. Via the presented method minimal invasisve detection and therapy of perforation can be conducted safely and can lead to reduction of morbidity.

Primary Malignant Vaginal Melanoma - Case Report and Review of the Literature

With fewer than 250 cases published worldwide, primary vaginal melanoma is an extremely rare malignant entity which is mostly diagnosed in advanced stages. The estimated incidence of vaginal melanoma is 0.026/100 000 women per year. The poor prognosis for advanced tumour stages and different therapies used in very limited numbers of patients require precise preoperative staging and a planned interdisciplinary therapeutic approach.

Influence of procalcitonin on decision to start antibiotic treatment in patients with a lower respiratory tract infection: insight from the observational multicentric ProREAL surveillance

Procalcitonin (PCT)-guided antibiotic stewardship is a successful strategy to decrease antibiotic use. We assessed if clinical judgement affected compliance with a PCT-algorithm for antibiotic prescribing in a multicenter surveillance of patients with lower respiratory tract infections (LRTI). Initiation and duration of antibiotic therapy, adherence to a PCT algorithm and outcome were monitored in consecutive adults with LRTI who were enrolled in a prospective observational quality control. We correlated initial clinical judgment of the treating physician with algorithm compliance and assessed the influence of PCT on the final decision to initiate antibiotic therapy. PCT levels correlated with physicians' estimates of the likelihood of bacterial infection (p for trend <0.02). PCT influenced the post-test probability of antibiotic initiation with a greater effect in patients with non-pneumonia LRTI (e.g., for bronchitis: -23 % if PCT ≤ 0.25 μg/L and +31 % if PCT > 0.25 μg/L), in European centers (e.g., in France -22 % if PCT ≤ 0.25 μg/L and +13 % if PCT > 0.25 μg/L) and in centers, which had previous experience with the PCT-algorithm (-16 % if PCT ≤ 0.25 μg/L and +19 % if PCT > 0.25 μg/L). Algorithm non-compliance, i.e. antibiotic prescribing despite low PCT-levels, was independently predicted by the likelihood of a bacterial infection as judged by the treating physician. Compliance was significantly associated with identification of a bacterial etiology (p = 0.01). Compliance with PCT-guided antibiotic stewardship was affected by geographically and culturally-influenced subjective clinical judgment. Initiation of antibiotic therapy was altered by PCT levels. Differential compliance with antibiotic stewardship efforts contributes to geographical differences in antibiotic prescribing habits and potentially influences antibiotic resistance rates.

A 24-week, multicentre, open evaluation of the clinical effectiveness of the rivastigmine patch in patients with probable Alzheimer's disease

BACKGROUND

Cholinesterase inhibitors form the mainstay of treatment for persons with mild-to-moderate Alzheimer's disease (AD). The rivastigmine patch may increase compliance and the proportion of patients maintaining an efficacious dose compared with oral cholinesterase inhibitors.

OBJECTIVE

To investigate the proportion of patients who reached and maintained the target rivastigmine patch dose compared with the target rivastigmine capsule dose reported in clinical trials.

METHODS

This was a multicentre, 24-week, open-label study in persons with probable AD and a Mini-Mental State Examination (MMSE) score of ≥ 10 and ≤ 26. The primary outcome was the proportion of patients (ITT population) treated with 9.5 mg/24 h rivastigmine patch for at least 8 weeks at week 24. Secondary outcomes included week 24 MMSE, Alzheimer's Disease Cooperative Study-Clinical Global Impression of Change (ADCS-CGIC), Trail Making Test Part A (TMT-A) and Alzheimer's Disease Cooperative Study-Activities of Daily Living (ADCS-ADL) scores.

RESULTS

Overall, 208 participants received treatment and 155 (74.5%) completed the study. Within the ITT population, 147/182 patients (80.8%; 95% CI 75.0-86.5%) were treated for at least 8 weeks with the 9.5 mg/24 h rivastigmine patch; 135/182 patients (74.2%; 95% CI 67.8-80.5%) were treated for at least 8 weeks and completed the study. The most common adverse events were nausea (10.1% of patients), erythema (8.7%), pruritus (8.2%) and vomiting (7.2%). At week 24, patients treated with the rivastigmine patch showed improvements on MMSE, ADCS-ADL, ADCS-CGIC and TMT-A scores. Caregivers reported acceptance, preference and satisfaction with the patch.

CONCLUSION

Transdermal delivery may allow more patients to reach and maintain therapeutic doses of rivastigmine compared with oral rivastigmine.

Conversion from carbamazepine or oxcarbazepine to topiramate in adolescents and adults with epilepsy

OBJECTIVE

To explore effectiveness, tolerability and changes in quality of life in patients with epilepsy converting to topiramate (TPM) from carbamazepine (CBZ) or oxcarbazepine (OXC) due to insufficient effectiveness and/or tolerability.

METHODS

A multicenter, open-label, non-interventional trial was used to examine patients (> or = 12 years) with epilepsy, changing to TPM monotherapy from baseline mono- or combination therapy with CBZ or OXC. TPM was added to the existing antiepileptic drug (AED) treatment and started at a dose of 25 mg once daily. The dose was titrated up with 25 mg/day increments, once every 1-2 weeks, until a final dose between 50 and 200 mg/day was reached. On the basis of clinical judgment, the treating physician decided whether or not the existing AED treatment with CBZ or OXC could then be withdrawn. Type and number of seizures, preferred TPM dose, quality of life (QOLIE-10 questionnaire), subjective perception of improvement and adverse events (AE) were documented.

RESULTS

140 patients (53.5% women, mean age 47 years) decided to switch to TPM due to insufficient effectiveness (75% of patients) and/or poor tolerability (80%) of the CBZ/OXC treatment. Average duration of follow-up was 24 weeks with an overall discontinuation rate of 19.3%, mainly due to AEs (12.1%). At study endpoint, the intended shift to TPM monotherapy was achieved in 73% of patients at a median TPM dose of 100 mg/day. A seizure reduction of > or = 50% was achieved in 91% of patients in the last scheduled period (weeks 12-26); 62% of patients entering that period remained seizure free. Quality of life at endpoint improved significantly when compared with baseline for all domains of QOLIE-10 (P < 0.001). Most frequent AEs (reported by > or = 5% of patients) were paresthesia (9.3%), weight loss (7.9%), convulsions (5.7%) and memory disorders (5.0%).

CONCLUSION

In patients with epilepsy, previously not satisfactorily treated with CBZ or OXC, conversion to TPM may result in an improvement in seizure control as well as in quality of life.

[Back pain and acne conglobata: SAPHO syndrome]

We report on a young woman suffering from SAPHO syndrome with back pain and arthritis of the sternoclavicular joints. This inflammatory disorder of the osteoarticular system (synovitis, osteitis, and hyperostosis) is associated with severe acne or palmoplantar pustulosis. The patient was treated with pamidronate, NSAID and physiotherapy which improved the musculoskeletal symptoms completely. The acne was treated with isotretinoin.

[Secondary prevention of myocardial infarction in the Basse-Normandie region]

The objectives of this study were to determine post-infarction drug therapy at discharge from hospital and at one year in the Basse Normandie region (France) and the management of risk factors, to compare them with the practice recommended by the French Society of Cardiology and other recent references. Patients whose medical expenses were exonerated by the Social Security for primary myocardial infarction without a history of angioplasty or of coronary bypass grafting between February and September 2002 were reviewed. The data was researched from the hospital, the patient, the attending physician and the data bases of the Social Security. Four hundred and fifteen patients were included. At discharge from hospital the percentages of prescriptions of recommended drugs were as follows: betablockers 85%, antithrombotics 99%, ACE inhibitors 75%, lipid lowering drugs 90%; the four drug families were associated in 63% of cases. There was no significant difference in prescription between hospital discharge and the twelfth months except with regards to ACE inhibitors (68%) and the association of the four drug groups (54%). The prevalence of smoking, hypertension, diabetes, overweight, obesity and dyslipidaemia were respectively 40, 39, 9, 44, 20 and 81% at the time of infarction. At one year, the prevalence of smoking had fallen significantly to 16%; only 10.3% of patients had uncontrolled hypertension and only 29% had not obtained the recommended therapeutic target for LDL-cholesterol. The authors conclude that this analysis shows an adequation of drug prescription to current recommendations and an improvement in risk factor management which should, however, be pursued.

In vitro protection of plasma cholinesterases by metoclopramide from inhibition by mipafox

Metoclopramide (MCP) is a dopamine receptor antagonist and serotonin receptor agonist widely used as an antiemetic and gastric prokinetic drug. In addition MCP is a reversible inhibitor of cholinesterases from human central nervous system and blood. Metoclopramide may have a cholinesterase protective effect against inhibition by organophosphates. The purpose of the study was to quantify in vitro, by means of the IC(50) shift, the extent of MCP conferred protection, using mipafox (MPFX) as an inhibitor. Mipafox is a neuropathic organophosphate. Cholinesterase activities (with acetylthiocholine [ChE-A] and butyrylthiocholine [ChE-B] as substrates) in human plasma were measured photometrically in the presence of different MPFX concentrations and the IC(50) was calculated. Determinations were repeated in the presence of increasing MCP concentrations. It appears that the shift induced by the presence of MCP increases with the MCP concentration in a linear manner. In the presence of a clinically easily achievable plasma concentration of 1 micro M MCP, the IC(50) of MPFX for cholinesterase 'shifts' by a factor of ca. 3-6. The protective effect of MCP on cholinesterase could be of practical relevance in the treatment of organophosphate poisoning. We conclude that in vivo testing of MCP as an organophosphate protective agent is warranted.

Ceftriaxone acts synergistically with levofloxacin in experimental meningitis and reduces levofloxacin-induced resistance in penicillin-resistant pneumococci

Ceftriaxone acted synergistically with levofloxacin in time-killing assays in vitro over 8 h against two penicillin-resistant pneumococcal strains (WB4 and KR4; MIC of penicillin: 4 mg/L). Synergy was confirmed with the chequerboard method, showing FIC indices of 0.25. In the experimental rabbit meningitis model, ceftriaxone (1x 125 mg/kg) was slightly less bactericidal (-0.30 Deltalog(10) cfu/mL(.)h) compared with levofloxacin (-0.45 Deltalog(10) cfu/mL(.)h) against the penicillin-resistant strain WB4. The combination therapy (levofloxacin and ceftriaxone) was significantly superior (-0.64 Deltalog(10) cfu/mL(.)h) to either monotherapy. In cycling experiments in vitro, the addition of ceftriaxone at a sub-MIC concentration (1/16 MIC) reduced levofloxacin-induced resistance in the two strains KR4 and WB4. After 12 cycles with levofloxacin monotherapy, the MIC increased 64-fold in both strains versus a 16-fold increase with the combination (levofloxacin + ceftriaxone 1/16 MIC). In both strains, levofloxacin-induced resistance was confirmed by mutations detected in the genes parC and gyrA, encoding for subunits of topoisomerase IV and gyrase, respectively. The addition of ceftriaxone suppressed mutations in parC but led to a new mutation in parE in both strains.

Meropenem prevents levofloxacin-induced resistance in penicillin-resistant pneumococci and acts synergistically with levofloxacin in experimental meningitis

The aim of the present study was to investigate the potential synergy between meropenem and levofloxacin in vitro and in experimental meningitis and to determine the effect of meropenem on levofloxacin-induced resistance in vitro. Meropenem increased the efficacy of levofloxacin against the penicillin-resistant pneumococcal strain KR4 in time-killing assays in vitro and acted synergistically against a second penicillin-resistant strain WB4. In the checkerboard, only an additive effect (FIC indices: 1.0) was observed for both strains. In cycling experiments in vitro, levofloxacin alone led to a 64-fold increase in the MIC for both strains after 12 cycles. Addition of meropenem in sub-MIC concentrations (0.25 x MIC) completely inhibited the selection of levofloxacin-resistant mutants in WB4 after 12 cycles. In KR4, the addition of meropenem led to just a twofold increase in the MIC for levofloxacin after 12 cycles. Mutations detected in the genes encoding for topoisomerase IV (parC) and gyrase (gyrA) confirmed the levofloxacin-induced resistance in both strains. Addition of meropenem was able to completely suppress levofloxacin-induced mutations in WB4 and led to only one mutation in parE in KR4. In experimental meningitis, meropenem, given in two doses (2 x 125 mg/kg), produced a good bactericidal activity (-0.45 Deltalog10 cfu/ml.h) comparable to one dose (1 x 10 mg/kg) of levofloxacin (-0.44 Deltalog10 cfu/ml.h) against the penicillin-resistant strain WB4. Meropenem combined with levofloxacin acted synergistically (-0.93 Deltalog10 cfu/ml.h), sterilizing the CSF of all rabbits.

Cefotaxime acts synergistically with levofloxacin in experimental meningitis due to penicillin-resistant pneumococci and prevents selection of levofloxacin-resistant mutants in vitro

Cefotaxime, given in two doses (each 100 mg/kg of body weight), produced a good bactericidal activity (-0.47 Deltalog(10) CFU/ml. h) which was comparable to that of levofloxacin (-0.49 Deltalog(10) CFU/ml. h) against a penicillin-resistant pneumococcal strain WB4 in experimental meningitis. Cefotaxime combined with levofloxacin acted synergistically (-1.04 Deltalog(10) CFU/ml. h). Synergy between cefotaxime and levofloxacin was also demonstrated in vitro in time killing assays and with the checkerboard method for two penicillin-resistant strains (WB4 and KR4). Using in vitro cycling experiments, the addition of cefotaxime in sub-MIC concentrations (one-eighth of the MIC) drastically reduced levofloxacin-induced resistance in the same two strains (64-fold increase of the MIC of levofloxacin after 12 cycles versus 2-fold increase of the MIC of levofloxacin combined with cefotaxime). Mutations detected in the genes encoding topoisomerase IV (parC and parE) and gyrase (gyrA and gyrB) confirmed the levofloxacin-induced resistance in both strains. Addition of cefotaxime in low doses was able to suppress levofloxacin-induced resistance.

In vitro protection of plasma cholinesterases by metoclopramide from inhibition by paraoxon

Metoclopramide (MCP) is a dopamine receptor antagonist and serotonine receptor agonist widely used as an antiemetic and gastric prokinetic drug. In addition MCP is a reversible inhibitor of cholinesterases from human central nervous system and blood. MCP may have a cholinesterase protective effect against inhibition by organophosphates. The purpose of the study was to quantify "in vitro" by means of the IC(50)-shift the extent of MCP conferred protection, using paraoxon (POX) as an inhibitor. POX is a widely used organophospate responsible for a large number of accidental or suicidal exposures. Cholinesteratic activities (ChE) (with acetyl-thiocholine (A) and butyryl-thiocholine (B) as substrates) in human plasma were measured photometrically in the presence of different POX concentrations and IC(50) was calculated. Determinations were repeated in the presence of increasing MCP concentrations. It appears that the shift induced by the presence of MCP increases with the MCP concentration in a linear manner. In the presence of a clinically easily achievable plasma concentration of 1 micro M MCP the IC(50) of POX for ChE 'shifts' by a factor of approximately 2-3. The protective effect of metoclopramide on cholinesterases could be of practical relevance in the treatment of paraoxon poisoning. We conclude that in vivo testing of MCP as an organophosphate protective agent is warranted.

Serum beta-2-microglobulin in the differential diagnosis of monoclonal gammopathies

Serum beta-2-microglobulin (B2m) concentrations were determined in 43 southern African black patients with multiple myeloma (MM), in 130 black patients with monoclonal gammopathy of undetermined significance (MGUS) and in 70 control subjects. The results showed median values for serum B2m in patients with MM, MGUS and the control group to be 8.10 mg/l, 3.05 mg/l, and 2.35 mg/l, respectively; these values differed significantly from one another (P less than 0.01), even when patients with normal renal function (serum creatinine value less than 110 mumol/l) were considered separately. The median serum B2m concentration for IgG MM (22 cases) was 4.3 mg/l, for IgA MM (8 cases) 7.3 mg/l, and 24.2 mg/l for Bence Jones MM (12 cases). These differences were also significant (P = 0.001), but not in the restricted group of MM patients with normal renal function. In the 43 MM patients serum B2m concentrations had a significant positive correlation with serum creatinine (r = 0.706; P less than 0.005) and a significant negative correlation with haemoglobin values (r = -0.459; P = 0.006). In 28 MM patients with normal renal function, serum B2m values had a significant negative correlation with serum albumin (r = -0.602, P = 0.003). Sixty-five per cent of the 43 MM patients and 18.5% of the MGUS patients had raised serum B2m values (greater than 4.7 mg/l). An optimum cut-off value for serum B2m of 6.9 mg/l for differentiating MM from MGUS was determined using a classification rule. Despite lacking specificity, serum B2m measurement was useful in differentiating MM from MGUS, and was the best second choice variable in relation to serum albumin and haemoglobin in patients with normal renal function.