Re-Envisioning the Culture of Undergraduate Biology Education to Foster Black Student Success: A Clarion Call

The purpose of this paper is to present an argument for why there is a need to re-envision the underlying culture of undergraduate biology education to ensure the success, retention, and matriculation of Black students. The basis of this argument is the continued noted challenges with retaining Black students in the biological sciences coupled with existing research that implicates science contexts (i.e., the cultural norms, values, and beliefs manifesting through policies and practices) as being the primary source of the challenges experienced by Black students that lead to their attrition. In presenting this argument, we introduce the Re-Envisioning Culture Network, a multigenerational, interdisciplinary network comprised of higher education administrators, faculty, staff, Black undergraduate students majoring in biology, Black cultural artists, community leaders, and STEM professionals to work together to curate and generate resources and tools that will facilitate change. In introducing the REC Network and disseminating its mission and ongoing endeavors, we generate a clarion call for educators, researchers, STEM professionals, students, and the broader community to join us in this endeavor in fostering transformative change.

Measurement of serum zinc concentration in ruminants: a comparison of results from standard serum and specific trace element collection tubes

Aims: To evaluate agreement between the concentration of Zn in serum from samples collected from cattle and sheep into standard collection tubes for serum and from samples collected into tubes developed for trace element measurement. Methods: Eighty-eight animals (78 cattle and 10 sheep) on eight farms had paired blood samples collected into standard serum and trace element vacutainers. The paired samples were submitted the same day to the laboratory to be tested for the concentration of Zn in serum using atomic absorption spectrophotometry. The agreement between the paired results was then assessed using limits of agreement analysis. On one farm an additional 10 pairs of samples was taken from the same animals; this second set of paired samples was refrigerated for 48 hours prior to laboratory submission to identify the impact of delaying submission on the apparent concentration of Zn in serum. Results: The limits of agreement analysis found no evidence of a systematic difference between Zn concentrations in serum collected into standard serum tubes and into trace element tubes as neither the intercept nor the slope on the mean-difference plot were significantly different from zero. The SD of the difference between results increased as the concentration of Zn increased, so at the lowest Zn concentration reported in this study (6.9 μmol/L) the limits of agreement were ±1.07 μmol/L, while at the highest (23.5 μmol/L) they were ±3.39 μmol/L. Refrigerating the sample (as whole blood) for 48 hours prior to submission increased the apparent concentration of Zn in serum in both standard serum tubes and trace element tubes by 1.3 μmol/L (95% CI = 0.75-1.85). Conclusions: There was no evidence that the concentration of Zn in serum from standard serum tubes were artificially elevated. In contrast, delaying sample submission by 48 hours did elevate Zn concentrations. Clinical relevance: While these data apply only to the batch of vacutainers used in this study, there is unlikely to be much between batch variation in the potential for contamination. Thus these results suggest that monitoring zinc status in ruminants, by measuring the concentration of Zn in serum from samples collected into standard serum tubes does not result in clinically relevant alterations in Zn concentration compared to using specific trace element tubes. However delaying submission to the laboratory may result in significantly elevated concentrations of Zn in serum so should be avoided.

Vibrio damsela, a Marine Bacterium, Causes Skin Ulcers on the Damselfish Chromis punctipinnis

A previously undescribed marine bacterium, Vibrio damsela, was isolated from naturally occurring skin ulcers on a species of temperate-water damselfish, the blacksmith (Chromis punctipinnis). Laboratory infection of the blacksmith with Vibrio damsela produced similar ulcers. Vibrio damsela was pathogenic for four other species of damselfish but not for members of other families of fish. The bacterium has also been isolated from water and from two human wounds and may be a cause of human disease.

A prospective study of an algorithm using cardiac troponin I and myoglobin as adjuncts in the diagnosis of acute myocardial infarction and intermediate coronary syndromes in a veteran's hospital

BACKGROUND

Accurate and cost-effective evaluation of acute chest pain has been problematic for years. The high prevalence of missed myocardial infarctions (MI) has led to conservative triage behavior on the part of physicians, leading to expensive admissions to coronary care units. New algorithms are sorely needed for more rapid and accurate triage of patients with chest pain to appropriate treatment settings.

HYPOTHESIS

We sought to test an algorithm for rapid diagnosis of MI and acute coronary syndromes using cardiac troponin I (cTnI) and myoglobin as adjuncts to creatine kinase (CK)-MB. We hypothesized our algorithm would be both sensitive and specific at early time points, and would allow safe stratification of patients not ruling in by conventional CK-MB criteria.

METHODS

This was a 6-month prospective study of 505 consecutive patients who presented with chest pain at a university-affiliated veteran's hospital. The percentage of MIs at various time points was identified using combinations of markers. Safety outcomes were assessed by follow-up of patients discharged home. Cost savings analysis was assessed by surveying the physicians as to whether the use of the algorithm affected their disposition of patients. Forty-nine patients ruled in for MI. Using the combination of cTnI, 2-h doubling of myoglobin, and CK-MB, 37 (76%) ruled in at the time of presentation, 43 (88%) at 2 h, and 100% by 6 h.

RESULTS

Cardiac troponin I plus a 2-h myoglobin was as accurate as the combination of all three markers and performed better than CK-MB in detecting patients presenting late and as a predictor for complications when CK-MB was normal. Of the 456 patients with normal markers after 6 h, only 140 were sent to the coronary care unit (CCU), and 176 were sent home. A 3-month follow-up showed minimal adverse events. One-half of physicians completing a survey stated the use of markers changed their disposition of patients, leading to an estimated 6-month cost savings of a half-million dollars.

CONCLUSIONS

We developed an algorithm using troponin I and myoglobin as adjuncts to usual CK-MB levels that allowed for rapid and accurate assessment of patients with acute MI. It also afforded physicians important input into their decision making as to how best to triage patients presenting with chest pain. Their comfort in sending home certain subgroups of patients who otherwise would have been admitted to the CCU was rewarded with a good short-term prognosis and a large cost savings to the hospital.

Do fibre containing enteral diets have advantages over existing low residue diets?

This study investigated the influence of fibre on the pattern of absorption of protein and carbohydrate following administration of polymeric enteral diet and also the effect of added fibre on frequency of bowel action, stool weight and gastrointestinal side effects during enteral nutrition. No difference was seen in frequency of bowel action, stool weight or gastrointestinal side effects in five patients fed with either a fibre free polymeric diet or with the same diet augmented with 24 g fibre/24 h. Addition of fibre did not significantly alter breath hydrogen excretion. In an oral tolerance test on six normal subjects, the post prandial rises in blood glucose and levels of 17 amino acids were similar on ingestion of a fibre containing or fibre free test meal.

Failure of aneurysm sac shrinkage after endovascular repair; the effect of mural calcification

AIM

To evaluate the effect of abdominal aortic aneurysm wall calcification on subsequent sac shrinkage after endovascular repair.

MATERIALS AND METHODS

Seventy-three patients underwent endovascular aneurysm repair. The degree of sac wall calcification on pre-procedural computed tomography (CT) examination was graded from 1 to 4 according to the degree of circumferential involvement. On follow-up CT imaging, the maximum transverse diameter (MTD) of the sac was recorded, as well as the presence or absence of endoleak. In those patients with a non-shrinking aneurysm, but no CT evidence of endoleak, contrast-enhanced ultrasound (USS) was performed. Any patient with an endoleak, however diagnosed, was excluded from the study. Kruskal-Wallis and Spearman's rank correlation coefficient testing was applied to compare the degree of calcification and change in MTD.

RESULTS

Sixty-three pre-procedural CT images were available for calcification grading. Six of this group had endoleaks resulting in 57 sets of data being available for the study. A reduction in MTD occurred in 68.25% of these patients by 1 year post-procedure. Our figures show aortic calcification is inversely associated with MTD reduction at 6 months (p = 0.01), 1 year (p = 0.05) and 2 years (p = 0.05).

CONCLUSION

This study indicates that the degree of aortic wall calcification is significant in predicting MTD reduction post-endovascular repair. The possible mechanisms and implications of this are discussed.

Common treatment of polycystic ovarian syndrome and major depressive disorder: case report and review

We present the case of a young woman with treatment-resistant major depression, who presented to the Mood Disorders Clinic with a Hamilton Psychiatric Rating Scale for Depression (HAM-D-21) score of 28, after a year-long treatment with Effexor-XR. The patient also had untreated Polycystic Ovarian Syndrome (PCOS). The resolution of her depressive symptoms resulted from the treatment for PCOS with metformin and spironolactone. The patient remained euthymic 5 months after discontinuation of the antidepressant while continuing therapy for PCOS. We briefly overview of the pertinent literature of the pathophysiology of PCOS and affective disorders, highlighting an overlap in phenotypical presentations between these two disorders. Dysregulation of the hypothalamo-pituitary axis and various end organ systems are implicated in both PCOS and affective disorders. As such, several clinical and biochemical markers are common to both disorders, namely insulin resistance, obesity, and hyperandrogenism. In addition, these metabolic abnormalities are interrelated, causing women with PCOS or affective disorders to get caught in a "vicious cycle" of hormonal dysregulation. The case report presented here illustrates how treatment of symptoms such as insulin resistance and hyperandrogenism can lead to remission of major depressive disorder and PCOS. We suggest that through treatment of underlying metabolic defects, both the mood of the patient and the metabolic condition of PCOS can be assisted.

Suggested specifications for a standardized Addiction Severity Index database

The Addiction Severity Index (ASI) has become one of the most widely used instruments in the addictions field. As a result of its wide popularity, there are multiple versions of the instrument in use, and a wide range of computer systems used to collect and/or store ASI data. Thus, it has been difficult for different users and systems to share ASI data. This difficulty significantly reduces the value of the information for treatment providers, policy makers, and researchers. This article provides operational definitions and specifications for a "Standard ASI Database." Descriptions for standard variable names, data types, field lengths, value labels, range checks, and programming notes for all items in the fifth edition of the ASI are available electronically from the senior. Examples from the full protocol and the rationale for producing the Standard ASI Database elements are illustrated here. It is hoped that the format suggested will become the "industry standard" for ASI data storage among all users of the ASI and that, regardless of the software used or the method of data collection, there will be a single, standard format for all ASI databases. The potential applications from such a database would benefit treatment providers/clinicians and researchers as well as payers and policy makers.

Multiple feeding in wolf spiders: the effect of starvation on handling time, ingestion rate, and intercatch intervals in Lycosa lapidosa (Araneae : Lycosidae)

Multiple prey capture, the behaviour of a predator attacking prey whilst handling a previously caught item, occurs in a variety of spiders that do not build webs. The effects of recent feeding history on the frequency of multiple prey attacks, handling time, ingestion rate, and intercatch intervals were examined experimentally in the wolf spider Lycosa lapidosa McKay. Juvenile spiders were subjected to two different feeding regimes (starvation for 14 and 28 days) and then provided with two different prey types (blowflies, Lucilia cuprina, and crickets, Acheta domestica). These two starvation levels or prey types had little effect on the frequency (75%) of multiple prey attacks. Spiders ingested approximately half the weight of any captured prey, regardless of how many prey items they attacked. At the same time, the handling time per prey item decreased with an increasing number of prey attacked. This indicates a more efficient ingestion rate when more prey are consumed. While the attacking time for the first prey was the same for all treatments, the first intercatch interval was longer for spiders that were starved longer. Chronically starved L. lapidosa appear to secure a previously caught item rather than optimise their capture rate by attacking further available prey.

Mersilene suture as a vehicle for delivery of growth factors in tendon repair

Extensive clinical and laboratory studies have demonstrated that growth factors accelerate and modulate the wound-healing process. The purpose of this experiment was to apply the principles of growth factor-enhanced wound healing to an in vitro rat tendon model. A method was developed for covalently binding a biologically active peptide to nonabsorbable braided polyester suture (Mersilene). Sutures were treated with various growth factors, which included epidermal growth factor, platelet-derived growth factor, and keratinocyte growth factor, and bovine serum albumin was the control. Spectrophotometric assessment was used to verify the peptide's activity. The suture was subsequently placed through individual harvested rat flexor tendons, which were arranged in standard tissue culture conditions. Markedly increased cellular proliferation along the suture was appreciated on the tendons treated with epidermal growth factor-bound suture. Platelet-derived growth factor was shown to have a lesser effect, whereas keratinocyte growth factor had no visible effect on cellular proliferation. This preliminary study describes a new technique of binding growth factors to suture. It also demonstrates that the presence of growth factors may help facilitate flexor tendon healing and allow early postoperative rehabilitation to decrease adhesion formation.

The impact of food processing on the nutritional quality of vitamins and minerals

Processing (including preparation) makes food healthier, safer, tastier and more shelf-stable. While the benefits are numerous, processing can also be detrimental, affecting the nutritional quality of foods. Blanching, for example, results in leaching losses of vitamins and minerals. Also, milling and extrusion can cause the physical removal of minerals during processing. The nutritional quality of minerals in food depends on their quantity as well as their bioavailability. The bioavailability of key minerals such as iron, zinc and calcium is known to be significantly affected by the fiber, phytic acid, and tannin content of foods. Concentrations of these constituents are altered by various processing methods including milling, fermentation, germination (sprouting), extrusion, and thermal processing. Vitamins, especially ascorbic acid, thiamin and folic acid, are highly sensitive to the same processing methods. The time and temperature of processing, product composition and storage are all factors that substantially impact the vitamin status of our foods.

Automatic postoperative monitoring of infrainguinal bypass procedures

OBJECTIVE

To evaluate the usefulness of a portable, computer-based, oscillometric, noninvasive blood pressure monitor for the automatic surveillance of postoperative infrainguinal bypasses.

DESIGN

Prospective unblinded study.

SETTING

Regional tertiary care Veterans Affairs medical center.

PATIENTS

A total of 60 limbs were examined in 3 groups (n = 20 in each group): normal, asymptomatic volunteers; older patients with symptomatic peripheral vascular disease; and patients who had undergone infrainguinal bypass procedures.

INTERVENTIONS

Noninvasive blood pressure monitor pressures, complete lower extremity arterial studies with Doppler ankle-brachial index (ABI), segmental pressures, and pulse volume recordings were performed in all groups. The patients who had undergone surgery also had hourly noninvasive blood pressure measurements taken.

MAIN OUTCOME MEASURES

Ankle-brachial indices obtained with the noninvasive blood pressure monitor were compared with simultaneous manual Doppler ABIs and pulse volume recordings.

RESULTS

There was a significant overall correlation between the Doppler-derived ABIs and automatic oscillometric values (r = 0.89, P < .001). Although there was a slight difference in absolute values (+/-SEM) (0.90 +/- 0.03 vs 0.84 +/- 0.03, respectively), an excellent correlation was found between the 2 methods in the clinically relevant range of ABI values between 0.60 and 1.10. The oscillometric method, however, overestimated the ABI when it was less than 0.60 by the Doppler method (0.61 +/- 0.02 vs 0.44 +/- 0.03, P < .001) and underestimated it when it was more than 1.10 (1.05 +/- 0.02 vs 1.16 +/- 0.01, P < .001). (All values given as +/-SEM.) Oscillometric overestimation correlated with depressed pulse volume recording waveforms (P < .001) or diminished pulse volume recording amplitudes of less than 10 mm (P < .001).

CONCLUSION

The automatic oscillometric monitor provides a useful, accurate, objective, and quantitative method for postoperative bypass graft surveillance.

Open access echocardiography in management of heart failure in the community

OBJECTIVE

To assess the value of an open access echocardiography service.

DESIGN

Study of new open access service for general practitioners, who were invited to refer patients taking diuretics for suspected heart failure, untreated patients with symptoms of possible heart failure, and asymptomatic patients with risk factors for left ventricular systolic dysfunction.

SETTING

Regional cardiology centre.

SUBJECTS

259 consecutive patients.

MAIN OUTCOME MEASURES

Presence or absence of left ventricular systolic dysfunction and consequent changes in clinical management.

RESULTS

119 treated patients, 99 untreated patients, and nine asymptomatic patients were referred over five months. 32 were considered to be inappropriately referred. Among the treated patients, 31 had impaired left ventricular systolic function and five had valvular disease; angiotensin converting enzyme inhibitors were recommended for 34 of these patients. In addition, 53 were thought not to need diuretics. Eight untreated patients had impaired systolic function and six valvular disease.

CONCLUSIONS

The service was well used by general practitioners and led to advice to change management in more than two thirds of patients.

Prevalence of unsuspected abdominal aortic aneurysms in male veterans

Abdominal aortic aneurysms (AAA) are potentially lethal arterial lesions that are best managed by elective surgical repair. However, asymptomatic AAAs may go undetected on routine physical examination or patients with such lesions may not consult a physician. To determine the prevalence of asymptomatic AAAs in a high-risk population, we retrospectively reviewed all abdominal CT scans on veterans > 50 years of age that had been ordered for indications other than aneurysmal disease during a recent 10-month period. Of the 111 patients studied, 15 (13.5%) had suprarenal and/or infrarenal AAAs (one patient had both). Patients with AAAs were significantly older (p = 0.0001) and were heavier tobacco users (p = 0.003). For patients > 60 years of age with peripheral vascular occlusive disease and a history of tobacco use, there was a 29.2% prevalence for AAA compared with 0% in those without any of these risk factors (p = 0.04). There was a very definite trend suggesting that patients with peripheral vascular disease (p = 0.06) were more likely to have an AAA. Because of the high prevalence of AAAs found in this population we then conducted a prospective study over a 24-month period during which patients > 60 years of age with known peripheral vascular disease and a history of smoking who presented to the vascular laboratory for evaluation of problems not related to AAA were asked to undergo an abdominal CT scan. Fifty-six volunteers agreed to participate in the study. Seven patients had AAAs and one patient had an isolated iliac aneurysm, for a 14.3% overall prevalence of aneurysms.2+ d

Self-reported illness and risk behaviours amongst Canadian travellers while abroad

403 travellers who attended The University of Calgary International Travel Clinic between August 1, 1987 and June 1, 1988, were asked to return a questionnaire detailing health, illness and risk factors while abroad. Of the 296 respondents, most travelled for fewer than 6 weeks time; destinations were primarily areas where chloroquine-resistant Plasmodium falciparum had been reported. Diarrhea was experienced by 57.3% of respondents; eating food purchased from street vendors was found to be a significant risk factor. Travellers who made trips exceeding 60 days' duration were significantly more likely to experience skin rashes, fevers or diarrhea, although it could not be determined whether this was due to their higher likelihood of undertaking high-risk behaviours, or to a higher number of person-days at risk. The findings of this high rate of illness while abroad underscores the need for specific advice on appropriate risk avoidance behaviours when pre-travel medical visits occur. Further prospective studies to determine effectiveness of such advice, and the patterns of illness based on person-days at risk, are required.

Prevalence of hemodynamically significant stenosis of the carotid artery in an asymptomatic veteran population

The results of previous studies have suggested that significant stenosis of the carotid artery occurs in less than 6 per cent of asymptomatic patients. However, some populations studied were not representative of those seen by most vascular surgeons. Accordingly, we examined two cohorts of patients at the Veterans Administration Medical Center using Duplex scanning. There were 153 volunteers in group 1, all more than 50 years of age, who were being treated at our outpatient department for nonvascular problems. There were 116 patients of similar age in group 2 but who were known to have significant arterial occlusive disease of the lower extremity. The majority of patients were men with a mean age of 64.4 years. Risk factors in the total population included hypertension, diabetes mellitus, coronary arterial disease, peripheral vascular disease and smoking. Over-all, significant (greater than 50 per cent diameter) stenosis of the carotid artery was discovered in 25 of 269 patients. The prevalence for those in group 1 was 6.5 per cent versus 12.9 per cent for those in group 2 (p = 0.058). The prevalence in patients with cardiac disease was 15.2 per cent compared with 6.8 per cent in those without cardiac disease (p = 0.032). Smoking was associated with a 10.6 per cent rate of significant disease compared with a 2.3 per cent rate in nonsmokers (p = 0.065). Hypertension and diabetes were not significant risk factors. Significant stenosis of the carotid artery was found in seven of 40 patients in whom coronary arterial disease, peripheral vascular disease and smoking were all present.(ABSTRACT TRUNCATED AT 250 WORDS)

Solid-phase sample preparation method for prostaglandins: integration of procedures for isolation and derivatization for gas chromatographic determination

A procedure using a solid-phase support has been developed for the isolation and derivatization of prostaglandins from biological matrices. The styrene-divinylbenzene cross-linked copolymeric macroreticular resin, XAD-2, was used as an adsorbent for prostaglandin E2 from biological samples, as a support for the oximation of the carbonyl group and as a catalyst for pentafluorobenzylation. The reactor bed was then linked to a Florisil column for a final chromatographic clean-up. Matrix effects were found to affect the yield, but recovery of the desired electrophoric products was comparable with methods reported in the literature. The ease of sample preparation suggests that this technique may be a viable approach to automating the processes for preparing prostaglandins from biological matrices for gas chromatographic analysis.

Imipenem-cilastatin in the treatment of methicillin-sensitive and methicillin-resistant Staphylococcus aureus infections

Imipenem-cilastatin was evaluated for efficacy and toxicity as an antistaphylococcal agent in 23 patients; 11 of these patients were infected with methicillin-resistant Staphylococcus aureus (MRSA), and 12 were infected with methicillin-susceptible S. aureus (MSSA). There were 15 soft tissue, 5 endovascular, and 3 skeletal infections and a total of nine patients with bacteremia. As determined by in vitro susceptibility testing, the MICs for 90% of the MRSA and MSSA isolates tested were 6.25 and 0.39 micrograms/ml, respectively. Two MRSA isolates were resistant to a concentration of greater than 16 micrograms/ml. When 11 MRSA isolates and 7 MSSA isolates were incubated for 48 h the MICs for 90% of the isolates increased to greater than 50 micrograms/ml for the MRSA isolates and 6.25 micrograms/ml for the MSSA isolates. Three S. aureus isolates emerged resistant. Ten of 11 (91%) MRSA infections and 11 of 12 (92%) MSSA infections were clinically cured. Adverse reactions occurred in 25% of the imipenemcilastatin-treated patients. These reactions included gastrointestinal intolerance (7% of the patients), rash or pruritus (6%), eosinophilia (6%), thrombocytosis (4%), and a positive, direct Coomb test without hemolysis (3%). One of the two patients for whom therapy was discontinued because of gastrointestinal intolerance had antibiotic-associated colitis. Imipenem appears to be an effective antistaphylococcal agent against both MRSA and MSSA infections.

Effect of dithiothreitol treatment of plasma on automated anti-D assay

A study of automated anti-D quantitation on untreated and dithiothreitol (DTT) pre-treated plasma has been undertaken. The results indicate that in most cases pre-treatment of plasma with DTT causes a reduction in the anti-D level detected. In one case such treatment caused the anti-D level to fall to less than 50% of its original value. DTT treatment prior to quantitation may give a more accurate assessment of the IgG anti-D level present in plasma and thus be of assistance in the selection of suitable plasma for anti-D immunoglobulin preparation. The technique may also have applications in the diagnosis and management of haemolytic disease of the newborn.

Relation between osmolality of diet and gastrointestinal side effects in enteral nutrition

One hundred and eighteen patients with normal gastrointestinal function were randomly allocated to one of three feeding regimens in a double blind study to determine the relation between the tonicity of the diet and gastrointestinal side effects related to the diet and to evaluate the efficacy of "starter" regimens in reducing gastrointestinal side effects during enteral nutrition. Patients received a hypertonic diet with an osmolality of 430 mmol (mosmol)/kg (group 1), the same diet but with the osmolality increasing from 145 to 430 mmol/kg over the first four days (group 2), or an isotonic diet (300 mmol/kg) (group 3). All diets were prepared aseptically and administered by 24 hour nasogastric infusion. The mean daily nitrogen intake in group 1 was significantly greater (p less than 0.05) than that in both groups 2 and 3, and the mean overall daily nitrogen balance was significantly better (p less than 0.05) in group 1 than groups 2 and 3. The incidence of side effects related to the diet was similar in all three groups, but diarrhoea was significantly (p less than 0.001) associated with concurrent treatment with antibiotics. These findings show that undiluted hypertonic diet results in significantly better nitrogen intake and balance, that starter regimens reduce nutrient intake but not symptoms, and that diarrhoea is significantly related to treatment with antibiotics and not to administration of an undiluted hypertonic polymeric diet.

A controlled trial of aseptic enteral diet preparation — Significant effects on bacterial contamination and nitrogen balance

This study was performed to evaluate the clinical effectiveness of the 'standard' and aseptic enteral diet preparation techniques and to investigate the relationship between bacterial contamination of diets and symptoms during enteral nutrition. In this controlled study patients were prescribed isonitrogenous polymeric diets prepared using either 'standard' or aseptic techniques, administered by 24 nasogastric infusion. 'Standard' diet preparation resulted in significant bacterial contamination (p<0.01), but this did not increase incidence of diet related symptoms. Use of sterile techniques permitted safe use of large volumes (1.5-2 litre) containers, and this resulted in significantly better nitrogen intake (p<0.05) and balance (p<0.05).

Diabetic diets: high carbohydrate combined with high fiber

The ideal level of carbohydrate intake for diabetics placed on high-fiber diets is unknown. Nineteen diabetics, therefore, took part in a total of twenty-four 5-day studies of fiber supplementation (guar) with carbohydrate intakes ranging from 22 to 61% of total calories. Where carbohydrate formed more than 40% of the calorie intake, there was a mean 64% reduction in glycosuria over the last 2 days on guar (P < 0.001, 14 studies, 11 patients). No significant reduction in glycosuria was seen in the 10 studies on lower carbohydrate intakes. This suggests that dietary fiber supplements in diabetes should be given against a background of higher rather than lower carbohydrate intake.