Starting from the needs: what are the appropriate sources to co-create innovative solutions for persons with disabilities?

PURPOSE

Technical solutions could facilitate activities and participation in individuals with disabilities. For the development of solutions, hackathons are a method of interdisciplinary collaboration. For hackathon, the definition of pain points that require solutions is crucial. We aimed to determine engineers' preferences and expectations regarding pain point qualities.

METHODS

We used a collaborative approach involving individuals with disability, families, and healthcare professionals to determine pain points for use by engineering students during a disability Hackathon. A pain point bank was built using 3 upstream sources: a survey (350 responses, 20 pain points selected), interviews (8 children, 13 pain points), and a multidisciplinary workshop based on design thinking methods (45 people, 32 pain points). A fourth source was 20 adults with disabilities present during the Hackathon. Engineering students rated pain point qualities from each source in a questionnaire that included closed questions relating to predefined criteria: achievability, specificity, relevance and attractiveness and open questions to collect non-predefined quality criteria.

RESULTS

Pain points from the workshop were most frequently used (48%); followed by on-site discussions with mentors (43%), the survey (38%), and interviews (31%). On-site discussions received the highest quality ratings followed by the workshop, survey, and interviews. Three quality criteria emerged from the responses to open questions: "representative", "empathy", and "real-need".

CONCLUSIONS

To be actionable by engineers, pain points must relate to real needs, be achievable, specific, relevant and attractive but also representative and arouse empathy. We devised a checklist of qualities along with a toolbox of methods to achieve each.

Implications For RehabilitationThe first step of the development of technical solutions for children and individuals with disabilities is the identification of their needs and their adequate formulation to be submitted to technical solutions providers.Daily life needs of individuals with disability were gathered for an engineering hackathon and proposed as pain points to 400 engineering students.To facilitate the development of solutions by engineers, pain points must relate to real needs, be specific, relevant, achievable and attractive; be representative and arouse empathy; a toolbox of needs collection methods is proposed to achieve each of those qualities.Discussions with individuals with disability and health professionals should be provided.

Using the gross motor function measure evolution ratio to compare different dosage of hyperbaric treatment with conventional therapies in children with cerebral palsy - could it end the controversy?

The Gross Motor Function Measure is used in most studies measuring gross motor function in children with cerebral palsy. In many studies, including those evaluating the effect of hyperbaric treatment, the Gross Motor Function Measure variations were potentially misinterpreted because of the lack of control groups. The Gross Motor Function Measure Evolution Ratio (GMFMER) uses historical data from the Gross Motor Function Classification System curves and allows to re-analyze previous published studies which used the Gross Motor Function Measure by considering the natural expected evolution of the Gross Motor Function Measure. As the GMFMER is defined by the ratio between the recorded Gross Motor Function Measure score increase and the expected increase attributed to natural evolution during the duration of the study (natural evolution yields a GMFMER of 1), it becomes easy to assess and compare the efficacy of different treatments.

Objective

The objective of this study is to revisit studies done with different dosage of hyperbaric treatment and to compare the GMFMER measured in these studies with those assessing the effects of various recommended treatments in children with cerebral palsy.

Methods

PubMed Searches were conducted to included studies that used the Gross Motor Function Measure to evaluate the effect of physical therapy, selective dorsal rhizotomy, botulinum toxin injection, hippotherapy, stem cell, or hyperbaric treatment. The GMFMER were computed for each group of the included studies.

Results

Forty-four studies were included, counting 4 studies evaluating the effects of various dosage of hyperbaric treatment in children with cerebral palsy. Since some studies had several arms, the GMFMER has been computed for 69 groups. The average GMFMER for the groups receiving less than 2 h/week of physical therapy was 2.5 ± 1.8 whereas in context of very intensive physical therapy it increased to 10.3 ± 6.1. The GMFMER of stem cell, selective dorsal rhizotomy, hippotherapy, and botulinum toxin treatment was, 6.0 ± 5.9, 6.5 ± 2.0, 13.3 ± 0.6, and 5.0 ± 2.9, respectively. The GMFMER of the groups of children receiving hyperbaric treatment were 28.1 ± 13.0 for hyperbaric oxygen therapy and 29.8 ± 6.8 for hyperbaric air.

Conclusion

The analysis of the included studies with the GMFMER showed that hyperbaric treatment can result in progress of gross motor function more than other recognized treatments in children with cerebral palsy.

Glycopyrronium 320 μg/mL in children and adolescents with severe sialorrhoea and neurodisabilities: A randomized, double-blind, placebo-controlled trial

AIM

To investigate the efficacy, safety, and impact on quality of life (QoL) of an oral formulation of 320 μg/mL glycopyrronium designed for children.

METHOD

A double-blind, placebo-controlled SALIVA (Sialanar plus orAl rehabiLitation against placebo plus oral rehabilitation for chIldren and adolescents with seVere sialorrhoeA and neurodisabilities) trial was conducted. Children (3-17 years) with neurodisabilities and severe sialorrhoea (modified Teachers Drooling Scale ≥6) were randomized to 320 μg/mL glycopyrronium or placebo, in addition to non-pharmacological standard care.

RESULTS

Of 87 participants, 44 were aged 10 years or under and 43 had cerebral palsy. The primary endpoint, change in total Drooling Impact Scale (DIS) score from baseline to day 84, was significantly greater (improved) with 320 μg/mL glycopyrronium versus placebo (median [quartile 1, quartile 3] -29.5 [-44.5, 0] vs -1 [-16, 5]; p < 0.001), an effect also observed at day 28 (median - 25 vs -2; p < 0.01). Significant reduction in bibs/clothes used per day was seen with glycopyrronium versus placebo at day 84 (median - 2 vs 0; p < 0.01). Glycopyrronium significantly improved DIS items 9 and 10 related to the extent that drooling affects the child's and family's life (p ≤ 0.03). Adverse events were reported by 77.3% and 69.8% of children with glycopyrronium and placebo respectively; the most common treatment-related adverse event was constipation (20.5% and 16.3%).

INTERPRETATION

The formulation of 320 μg/mL glycopyrronium significantly improved drooling and reduced its impact on QoL, with good tolerability in children with neurodisabilities.

Assistive Products and Technology to Facilitate Activities and Participation for Children with Disabilities

We aimed to identify activity limitations and participation restrictions encountered by children and youth with disabilities for which assistive products and technology could be helpful. We used a convergent, parallel, mixed-methods design involving a nationwide, French survey composed of closed questions (quantitative) and open questions (qualitative) that enlightened the quantitative data. A total of 1055 responses were received, and 962 included: 92 from children and youth with disabilities, 493 from relatives and 377 from professionals. Difficulties frequently checked and described in detail were participation in recreational activities, leaving the house and traveling, participating in a group, and getting ready. Transversal explanations for difficulties were spontaneously provided (e.g., lack of accessibility and mobility). Solutions proposed included personal assistive devices to facilitate home life, high-tech devices, devices to compensate for impaired body functions, and adaptation of the familiar environment and daily activities. Few public solutions were proposed. The necessity of human assistance was emphasized. The mixed-methods design and involvement of different stakeholders identified common, macroscopic trends in difficulties encountered and desired solutions. Products and technology are required in the following domains: the familiar environment, accessibility and mobility, sports and leisure, high-technology, and family support. We provide suggestions to facilitate the development of innovative solutions.

Safety and adherence of pressure garment therapy in children with upper limb unilateral cerebral palsy. Results from a randomized clinical trial ancillary analysis

Background

This study was conducted to assess the safety and adherence of the use of a PGT (Pressure Garment Therapy) Lycra® sleeve to treat upper limb unilateral cerebral palsy (UCP) in children.

Methods

This study was conducted as a prospective, placebo-controlled, double-blinded, randomized monocenter study. Included in the study were 58 UCP children, 49 of whom were analyzed. 25 children (mean age 6.6 ± 1.6 years; 12 girls) were allocated to the active group vs. 24 (mean age 6.7 ± 1.6 years; 10 girls) in the placebo group. The intervention consisted of an active PGT Lycra® arm sleeve manufactured to generate a homogeneous pressure ranging from 15 to 25 mmHg. The placebo PGT Lycra® sleeve was manufactured to generate a homogeneous pressure under 7 mmHg. The time of wearing period was set at 3 h/day at minimum and 6 h/day at maximum, over the course of 6 months. The main outcome measures were safety outcomes including the number and intensity of Adverse Events of Special Interest (AESIs). AESIs were defined as adverse events imputable to compressive therapy and Lycra® wearing. Level of adherence was expressed in percentage of number of days when the sleeve was worn for at least 3 h per day compared to length of duration in days (start and end date of wearing period).

Results

Frequency of AESIs were very low and no different between groups (4.12 ± 11.32% vs. 1.83 ± 3.38%; p = 0.504). There were no differences in adherence (91.86 ± 13.86% vs. 94.30 ± 9.95%; p = 0.425).

Conclusion

The use of PGT Lycra® arm sleeve in children with UCP is safe and well-tolerated with a very good adherence. The low rate of AESIs is promising for further randomized clinical trials on efficacy.

Hyperbaric oxygen in children with cerebral palsy: A systematic review of effectiveness and safety

PURPOSE

To report current evidence regarding the effectiveness of hyperbaric oxygen therapy (HBOT) on the impairments presented by children with cerebral palsy (CP), and its safety.

MATERIALS AND METHODS

PUBMED, The Cochrane Library, Google Scholar, and the Undersea and Hyperbaric Medical Society database were searched by two reviewers. Methodological quality was graded independently by 2 reviewers using the Physiotherapy Evidence Database assessment scale for randomized controlled trials (RCTs) and the modified Downs and Black (m-DB) evaluation tool for non RCTs. A meta-analysis was performed where applicable for RCTs.

RESULTS

Five RCTs were identified. Four had a high level of evidence. Seven other studies were observational studies of low quality. All RCTs used 100% O2, 1.5 to 1.75 ATA, as the treatment intervention. Pressurized air was the control intervention in 3 RCTs, and physical therapy in 2. In all but one RCTs, similar improvements were observed regarding motor and/or cognitive functions, in the HBOT and control groups. Adverse events were mostly of mild severity, the most common being middle ear barotrauma (up to 50% of children).

CONCLUSION

There is high-level evidence that HBOT is ineffective in improving motor and cognitive functions, in children with CP. There is moderate-level evidence that HBOT is associated with a higher rate of adverse events than pressurized air in children.

PROPENSIX: pressure garment therapy using compressive dynamic Lycra® sleeve to improve bi-manual performance in unilateral cerebral palsy: a multicenter randomized controlled trial protocol

Background

Upper limb impairment affects activity and participation in children with unilateral cerebral palsy (UCP). Pressure garment therapy (PGT) using compressive dynamic Lycra^® garments is an innovative intervention proposed for the management of cerebral palsy consequences. The PROPENSIX study aims to evaluate the efficacy of a therapy using a Lycra^® sleeve as compared to a placebo sleeve to improve bi-manual performance measured by the Assisting Hand Assessment (AHA) in children with unilateral cerebral palsy.

Methods

The PROPENSIX trial is a multicenter, prospective, placebo-controlled, double-blinded, randomized study. One hundred children with UCP, aged from 5 to 10, are randomly assigned as soon as they are recruited in a 1:1 ratio to perform usual daily activities, especially activities involving bimanual performances, with Lycra^® sleeve or placebo sleeve during 6 months. The primary endpoint is the change in bimanual performance from inclusion to 6 months, evaluated by AHA. The secondary endpoints evaluate changes from inclusion to 6 months in other dimensions of the International Classification of Functioning (ICF), upper limb movement capacity assessed by Quality of Upper Extremity Skill Test (QUEST), and health-related quality of life evaluated by Pediatric Quality of Life Inventory 3.0 Cerebral Palsy Module (PedsQLTM 3.0 CP Module) and in body structures and functions domain assessed by neuro-orthopedic examination and somatosensory evoked potentials (SEP).

Discussion

The PROPENSIX study is the largest randomized controlled trial (RCT) aiming to evaluate the efficacy of a PGT using compressive dynamic Lycra^® sleeve in UCP. Enhancement of children’s bimanual performance at the end of the 6 months wear of the Lycra^® sleeve should improve evidence regarding this type of treatment and expand discussion about their recommendation in clinical practice. Data from secondary outcomes assessments should bring interesting arguments to discuss the Lycra^® sleeve action on mobility, tonus, and sensory impairments in children with unilateral cerebral palsy.

Trial registration

ClinicalTrials.govNCT02086214. Retrospectively registered on March 13, 2014

Trial status

Study start data: December 2012. Recruitment status: completed. Primary completion date: April 2021. Estimated study completion date: December 2022. Protocol version 10 (date: February 2018).

Assessing the contribution of lower limb mobilization, in the supine position, on shoulder-pelvis girdles dissociation

BACKGROUND

Several articular, muscular and neurological diseases generate mobility loss in the shoulder and pelvis girdles. Joint mobilization contributes to improving shoulder-pelvis girdles dissociation, but current mobilization techniques are not always successful and standardized. A robotic medical device, DPA Med®, by inducing trunk mobilization through lower limb oscillation has been developed for producing such a shoulder-pelvis girdles dissociation and is already used worldwide in rehabilitation hospitals.

RESEARCH QUESTION

To determine the optimal lower limb oscillation frequency that generated the best shoulder-pelvis girdles dissociation using the DPA Med® device.

METHODS

Thirty healthy adult volunteers (mean age: 38.6 [SD 15.2] years, mean height: 174 [SD 11.9] cm, mean body mass: 70.3 [SD 14.7] kg) participated in this prospective study. A kinematic analysis quantified pelvic and shoulder girdle mobility (rotation and lateral tilt) at different DPA Med® frequencies, from 0.5 Hz to 1 Hz. A visual analysis of the lower limb movement was also performed, using video sensors, to better understand the kinematics involved.

RESULTS

All DPA Med® frequencies have shown significant shoulder-pelvis girdles dissociation (p < 0.05). This study established an optimal oscillation frequency with the minimal interindividual variability at 0.808 Hz. It induced pelvic mobility similar to that of normal gait, in the transverse and frontal planes (10.3°, SD 2.9°, and 12.0°, SD 2.2°, respectively). This trunk mobility was achieved by producing a lemniscate-shaped motion in the lower limbs (an eight-shaped motion in the transverse plane).

SIGNIFICANCE

This study has shown that the DPA Med® device is able to induce shoulder-pelvis girdles dissociation similar to that of normal gait and allowed to establish the existence of an optimal DPA Med® oscillation frequency for lower limb mobility at 0.808 Hz. Further studies are required to evaluate its potentially benefits on gait disorders.

Patterns of upper limb muscle activation in children with unilateral spastic cerebral palsy: Variability and detection of deviations

BACKGROUND

The aim of this study was two-fold: (1) to quantify the variability of upper limb electromyographic patterns during elbow movements in typically developing children and children with unilateral spastic cerebral palsy, and to compare different amplitude normalization methods; (2) to develop a method using this variability to detect (a) deviations in the patterns of a child with unilateral spastic cerebral palsy from the average patterns of typically developing children, and (b) changes after treatment to reduce muscle activation.

METHODS

Twelve typically developing children ([6.7-15.9yo]; mean 11.0 SD 3.0yo) and six children with unilateral spastic cerebral palsy ([7.9-17.4yo]; mean 12.4 SD 4.0yo) attended two sessions during which they performed elbow extension-flexion and pronation-supination movements. Surface electromyography of the biceps, triceps, brachioradialis, pronator teres, pronator quadratus, and brachialis muscles was recorded. The Likelihood method was used to estimate the inter-trial, inter-session, and inter-subject variability of the electromyography patterns for each time point in the movement cycle. Deviations in muscle patterns from the patterns of typically developing children and changes following treatment were evaluated in a case study of a child with cerebral palsy.

FINDINGS

Normalization of electromyographic amplitude by the mean peak yielded the lowest variability. The variability data were then used in the case study. This method detected higher levels of activation in specific muscles compared with typically developing children, and a reduction in muscle activation after botulinum toxin A injections.

INTERPRETATION

Upper limb surface electromyography pattern analysis can be used for clinical applications in children with cerebral palsy.

Deinococcus as new chassis for industrial biotechnology: biology, physiology and tools

Deinococcus spp are among the most radiation-resistant micro-organisms that have been discovered. They show remarkable resistance to a range of damage caused by ionizing radiation, desiccation, UV radiation and oxidizing agents. Traditionally, Escherichia coli and Saccharomyces cerevisiae have been the two platforms of choice for engineering micro-organisms for biotechnological applications, because they are well understood and easy to work with. However, in recent years, researchers have begun using Deinococcus spp in biotechnologies and bioremediation due to their specific ability to grow and express novel engineered functions. More recently, the sequencing of several Deinococcus spp and comparative genomic analysis have provided new insight into the potential of this genus. Features such as the accumulation of genes encoding cell cleaning systems that eliminate organic and inorganic cell toxic components are widespread among Deinococcus spp. Other features such as the ability to degrade and metabolize sugars and polymeric sugars make Deinococcus spp. an attractive alternative for use in industrial biotechnology.

Effect of glutamine on glucose metabolism in children with Duchenne muscular dystrophy

BACKGROUND & AIMS

Glutamine is a potent gluconeogenic precursor and stimulates insulin secretion. Glutamine's effect on glucose metabolism in Duchenne muscular dystrophy (DMD) has never been studied. To determine plasma glucose and insulin concentrations measured during and after glutamine administration in DMD boys. We hypothesized that glutamine can modulate whole body glutamine-glucose metabolism in DMD, a genetically determined disease.

METHODS

As secondary endpoints of a randomized crossover trial in 30 prepubertal DMD boys, we measured fasting blood glucose, insulin and the Homeostasis Model Assessment (HOMA) index after daily oral glutamine (0.5 g kg(-1) d(-1)) for 4 months versus placebo. In a separate time series trial in 6 prepubertal DMD boys, we measured the same endpoints as well as plasma glutamine and whole body glucose turnover (Ra,glc) (primed continuous i.v. infusion of d-[6,6-(2)D]glucose), while participants received acute oral glutamine (0.5 g kg(-1) d(-1)) continuously for 5 h.

RESULTS

In the randomized trial, baseline measurements of HOMA correlated with age (r = 0,51, p = 0.007) and percent fat estimated by bioelectrical impedance analysis (BIA) (r = 0.39, p = 0.047). After 4 months glutamine supplementation, we observed no treatment or order effect on HOMA or insulin. During acute glutamine for 5 h (time series trial), plasma glutamine doubled and was associated with increased plasma insulin concentration (10.42 ± 2.54 vs 7.32 ± 1.86, p = 0.05) with no effect on plasma glucose, HOMA or Ra,glc.

CONCLUSIONS

Acute glutamine transiently stimulates insulin secretion in DMD boys, which could be mediated by plasma glutamine concentrations. Fasting insulin concentration and HOMA might provide quantifiable indices of disease progression.

Assessing change in body composition in children with Duchenne muscular dystrophy: anthropometry and bioelectrical impedance analysis versus dual-energy X-ray absorptiometry

BACKGROUND & AIMS

To compare the ability of bioelectrical impedance analysis (BIA) and skinfold thickness (ST) measurements to estimate changes in body composition in Duchenne muscular dystrophy (DMD).

METHODS

A secondary analysis was performed on 26 ambulatory DMD boys aged 3-11 y selected for a randomised trial of glutamine supplementation. We assessed fat free mass (FFM) and percentage fat mass (%FM) by BIA (monofrequency (50kHz) unit), ST measurements and a criterion method, dual-energy X-ray absorptiometry (DXA), and repeated these measures 5 mo later at 3 outpatient clinical investigation centers in France.

RESULTS

When compared with DXA reference method, ST overestimated change in FFM (P<0.01), whereas BIA estimates did not differ from DXA. Concordance plots revealed that when compared with DXA, ST overestimated the increase in FFM (mean: 0.6 kg; 95% CI: 0.17 to 0.99) which led to an underestimation in %FM change (mean: -1.4%; 95% CI: -2.6 to -0.2), whereas BIA estimated change in FFM (mean: -0.05 kg; 95% CI: -0.39 to 0.29) and %FM (mean: 1.3%; 95% CI: -0.06 to 2.7) more accurately.

CONCLUSIONS

BIA method can be used to follow changes in nutritional status of ambulatory DMD children or to evaluate treatment efficacy.

Lack of functional benefit with glutamine versus placebo in Duchenne muscular dystrophy: a randomized crossover trial

Background

Oral glutamine decreases whole body protein breakdown in Duchenne muscular dystrophy (DMD). We evaluated the functional benefit of 4 months oral glutamine in DMD.

Methodology/Principal Findings

30 ambulant DMD boys were included in this double-blind, randomized crossover trial with 2 intervention periods: glutamine (0.5 g/kg/d) and placebo, 4 months each, separated by a 1-month wash-out, at 3 outpatient clinical investigation centers in France. Functional benefit was tested by comparing glutamine versus placebo on change in walking speed at 4 months. Secondary outcome measures were: 2-minute walk test, work, power, muscle mass (urinary creatinine), markers of myofibrillar protein breakdown (urinary 3-methyl-histidine/creatinine), serum creatine phospho-kinase, body composition (fat free mass, fat mass percentage), safety and oral nutrient intake. There was no improvement in the primary end point (walking speed) or in secondary measures of muscle function (2-minute walk test, work, power) in the glutamine group compared with placebo. However, subjects receiving glutamine or placebo showed no deterioration in functional measures over the course of the 9-month trial. No differences in muscle mass, markers of protein breakdown or serum creatine phosho-kinase were observed, except for a blunted increase in fat free mass in the glutamine group which led to a greater increase in fat mass percentage. Glutamine was safe and well-tolerated.

Conclusions

This trial did not identify additional benefit of 4 months oral glutamine over placebo on muscle mass or function in ambulatory DMD boys. Although apparently safe, current data cannot support routine supplementation in this population as a whole, until further research proves otherwise.

Trial Registration

ClinicalTrials.gov NCT00296621

Epithelial Phenotypes in the Developing Human Prostate

An intermediate population has been identified among prostate glands called transiently amplifying (TA) cells, which are characterized by coexpression of basal and luminal cytokeratins (CKs), high proliferation, and lack of p27 expression. These cells are rare in the normal adult prostate and increase in pretumoral conditions, but their importance in the developing gland remains unknown. We analyzed fetal prostates for the expression of CKs (5/6, 18, 19) and factors involved in proliferation and apoptosis: p63, Ki67, p27, epidermal growth factor (EGFR), Bcl2, androgen receptor (AR). Immunostaining was performed on a tissue microarray, including 40 prostates from fetuses aged 13-42 weeks and normal prostate tissue from 10 adults. In both solid buds and the basal compartment of canalized glands, cells expressed p63, CK5/6, CK19, CK18, BCL2, EGFR and were p27 negative. Luminal cells of fetal canalized glands continue to express CK19, EGFR, and BCL2, without p27 expression. In contrast, adult epithelial luminal cells showed diffuse AR and p27 expression, without CK19, BCL2, and EGFR staining. Proliferation was high and diffuse in fetal glands and rare and restricted to basal cells in adult glands. These results indicate that most fetal epithelial prostatic cells exhibit the phenotype of TA cells, suggesting their regulatory function in prostate development.

Technical and clinical evaluation of fructosamine determination in serum

We evaluated a serum fructosamine (glycated serum proteins) assay for efficacy in the diagnosis and follow-up of diabetic patients. A Roche reagent kit, based on nitroblue tetrazolium reduction in alkaline medium, was used in COBAS FARA centrifugal analyzer. We demonstrated that this method is precise, linear and unaffected by serum hemolysis. However, bilirubin affected the test positively and lipemia negatively. Fructosamine (F) correlated positively with total protein (P) (r = 0.809) and albumin (r = 0.746) in a group of 48 non-diabetic individuals. A good correlation was observed between F and glycated hemoglobin from the sera of 514 patients (r = 0.794). A better correlation (r = 0.838) was obtained when F was corrected for P concentration (F/P). Different F and F/P means were calculated only in patients with overt diabetes, compared to normals. Gestational diabetes was associated with a highly significant F increase. However, its low sensitivity (21%) precludes the use of F as an effective screening test for that condition. Nevertheless, because of its simplicity, low cost and rapidity in reflecting changes in the metabolic control of diabetes, F should be considered a valuable test to assess glycemic control in diabetic patients.

Analytical interference of drugs in clinical chemistry: I--Study of twenty drugs on seven different instruments

We have investigated the effect of 20 drugs on the accuracy of results obtained from seven instruments now widely used in clinical biochemistry laboratories: Abbott VP, aca II, Cobas Bio, Ektachem 400, Hitachi 705, KDA and SMAC. Eleven to 18 constituents were analysed on each instrument. Our results lead us to the following conclusions: (1) only rarely does drug interference with a method lead to a clinically significant change in a measured value; (2) the magnitude of the change may relate linearly or non-linearly to the drug concentration but is usually independent of the target analyte concentration; (3) interference with a chemical reaction on one instrument does not always mean that the same reaction will be altered in the same way on other instruments; (4) no interferences were found for drugs with therapeutic levels in the low micro-molar range; (5) in most cases the interference could not be predicted from the chemical nature of drug.

Analytical interference of drugs in clinical chemistry: II--The interference of three cephalosporins with the determination of serum creatinine concentration by the Jaffé reaction

It is well known that some cephalosporins interfere with the Jaffé reaction for creatinine measurement. This interference varies according to the thirteen instruments and eighteen methodologies studied. Our study has shown that: the proportion of picric acid, NaOH and serum have only a slight effect on the interference; the addition of a buffer to the NaOH solution increases the interference due to cephalothin and cephaloridine, but lessens that due to cefoxitin; dialysis decreases the interference; in kinetic methods, the choice of times at which readings are made influences the magnitude of the interference; a higher incubation temperature increases the effect of cefoxitin and decreases the effects of cephalothin and cephaloridine; pre-incubation with NaOH decreases the interference due to cefoxitin, but has no significant effect on the interference due to cephalothin or to cephaloridine.

A simple procedure for the preparation of concentrated sera

We shall describe a simple technique to prepare concentrated sera that will have a near normal osmolality. A pool of sera is first frozen for 72 h at -20 degrees C and then allowed to thaw at 6 degrees C for 16 h. Care is taken to avoid any shaking of the bottle. The surface serum is then cautiously aspirated with a pipette. The left-over serum is mixed and filtered. To decrease the osmolality of this concentrated serum, we treated it with 200 mg of resin (Rexyn AG 501, H-OH) per 5 mL serum and then filtered it to eliminate the resin. We studied the effects of the height of the liquid column, the freezing temperature, the volume of serum decanted, the resin concentration and the duration of the extraction step. We also evaluated the stability of this concentrated serum at 6 degrees C, -20 degrees C and -70 degrees C. We also verified whether readjustment of the pH of the concentrated resin-treated serum would have improved its stability at -20 degrees C.

Systemic tolerance of osmotically induced oncolysis in rats

Acute necrosis of R3230AC mammary tumor or thyroid carcinoma subcutaneously implanted in F344 rats was achieved by injection of a strongly hypertonic hexose and serotonin solution at 37 degrees C into and around the tumors. Changes in gross metabolism, hematology, and blood chemistry were then followed over a 9-day period, and they were most marked during or at the end of the first 24 hours. Food intake of the rats was sharply reduced, whereas drinking and diuresis were increased. Marked hemodilution and increased serum concentrations of aspartate aminotransferase, potassium, and uric acid were observed, as well as stable serum concentrations of sodium and chloride. Glucose overload, as opposed to fructose overload, led to secondary hypoglycemia. From day 2 food consumption returned to normal and increased thereafter. Water intake and urine output remained high. After an initial loss, body weight caught up with that of control rats. Hematocrit recovered partially, whereas blood chemistry progressively returned to about normal values.

Study of seasonal variations for eighteen biochemical parameters over a four-year period

The seasonal variations of eighteen parameters of a biochemical profile were studied under standardized conditions. More than 2,600 blood samples from a homogeneous group of women aged 30 to 39 years were processed on a well controlled instrument over a four-year period. Monthly means were first calculated and then seasonal means for two delimitations of seasons and for different combinations of years. Even though many statistically significant differences were found between seasons, only in the case of two parameters, uric acid and triglycerides, was the percentage of difference between the highest and the lowest seasonal means greater than the inter-assay CV of the methods. For these two parameters the results of other age groups of women and men were also computed. Uric acid was higher in summer compared to fall by 5% in the case of women aged 30-39 and by 7% in the case of men aged 30-39, the method inter-assay CV being 4.5%. Triglycerides were 6% higher during spring compared to fall for women aged 30-39, but surprisingly, 22% higher in winter compared to fall in the case of men aged 30-39. For younger groups of men the difference is much smaller and for men aged 20 to 25 years the difference is not significant. In general, we have been unable to confirm the variations previously reported by many authors.

[Reference values for 2 well-defined populations: newborn infants and post-partum women]

Reference values for two well defined populations, four day old newborns and post-partum women, are given for 19 parameters measured on a SMAC system. These values are respectively compared to those established previously for children from one to three year old and those of women aged 20-39. The values for the new borns are higher for eight parameters and lower for nine others. The values for post-partum women are higher for seven parameters and lower for six others. These two groups have therefore distinct reference values for most of the parameters studied.

The in vitro effect of drugs on biochemical parameters determined by a SMAC system

1. We have studied the in vitro effect of 39 drugs on 17 biochemical parameters determined by a SMAC System. Only two drugs were found to interfere: ascorbic and theophyline. 2. The ascorbic acid lowers the glucose and the bilirubine values; it increases the creatinine and the uric acid concentration. At concentration smaller than 5 mg/dl of this drug, these effects are negligible. 3. We have found a new drug interference: theophylline inhibits the alkaline phosphatase and LDH activities. This effect is not negligible on alkaline phosphatase for therapeutic levels of this drug; the action on LDH can be ignored at normal therapeutic range. 4. For a given drug, we have found different interference with biochemical parameters determined with various commercial lyophlised control sera or a liquid pool of sera. This indicates that the type of sera used in drug interference studies must be described.

SYNTHESIS OF 2-PYRROLECARBOXYLIC (C14O2H) ACID AND STUDY OF ITS METABOLISM IN THE INTACT RAT

A method is described for the synthesis of 2-pyrrolecarboxylic (C14O2H) acid (PCA), in 50% over-all yield, by carbonation in a closed system of pyrrylmagnesium bromide, using a small amount of radioactive carbon dioxide. Doses of the labelled substance were administered by intraperitoneal injection to young rats. A small fraction of the injected radioactive PCA was catabolized in the rat tissues in such a manner that only 5 to 6% of the isotope appeared in expired carbon dioxide within 24 hours. From 70 to 80% of the injected radioactivity was excreted in the urine collected for 24 hours. Unchanged PCA, pyrroylglycine, and a glucuronide of PCA were the three major radioactive products demonstrated in the urine.

SYNTHESIS OF 2-PYRROLECARBOXYLIC (C14O2H) ACID AND STUDY OF ITS METABOLISM IN THE INTACT RAT

A method is described for the synthesis of 2-pyrrolecarboxylic (C14O2H) acid (PCA), in 50% over-all yield, by carbonation in a closed system of pyrrylmagnesium bromide, using a small amount of radioactive carbon dioxide. Doses of the labelled substance were administered by intraperitoneal injection to young rats. A small fraction of the injected radioactive PCA was catabolized in the rat tissues in such a manner that only 5 to 6% of the isotope appeared in expired carbon dioxide within 24 hours. From 70 to 80% of the injected radioactivity was excreted in the urine collected for 24 hours. Unchanged PCA, pyrroylglycine, and a glucuronide of PCA were the three major radioactive products demonstrated in the urine.

THE FORMATION OF 2-PYRROLECARBOXYLIC ACID FROM HYDROXY-D- AND ALLOHYDROXY-D-PROLINE

Evidence is presented for the identity of chemically prepared 2-pyrrolecarboxylic acid and the metabolite formed in rat and human tissues from hydroxy-D-proline and allohydroxy-D-proline. 2-Pyrrolecarboxylic acid is not an intermediate in the biological degradation of natural hydroxyproline.

THE FORMATION OF 2-PYRROLECARBOXYLIC ACID FROM HYDROXY-D- AND ALLOHYDROXY-D-PROLINE

Evidence is presented for the identity of chemically prepared 2-pyrrolecarboxylic acid and the metabolite formed in rat and human tissues from hydroxy-D-proline and allohydroxy-D-proline. 2-Pyrrolecarboxylic acid is not an intermediate in the biological degradation of natural hydroxyproline.