Economic risks hidden in local water pollution and global markets: A retrospective analysis (1995-2010) and future perspectives on sustainable development goal 6

Pollution from untreated wastewater discharges depletes clean water supply for humans and the environment. It poses adverse economic impacts by determining agricultural yields, manufacturing productivity, and ecosystem functionality. Current studies mainly focus on quantity-related water scarcity assessment. It is unknown how low water quality amplifies local water stress and induces cascading economic risks globally. In this study, we estimated both quality and quantity-related water scarcity index (WSI), local economic water scarcity risk (WSR), and cascading virtual WSR evident in global trade markets across 40 major economies from 1995 to 2010. We find developing countries, e.g., India and China, witnessed fast growth in both quantity and quality-related WSI. Major developed economies, e.g., the US and Germany, experienced a modest increase in water stress but alleviated quality-related risks. Local economic risk (WSR) grew from $116B to $380B, with quality-related risks rising from 20 % to 30 %. Virtual economic WSR in global supply chains increased from $39B to $160B, with quality-related risks increasing from 19 % to 27 %. China became the top exporter of economic WSR, ranked above the US, France, and Japan, and the second-largest position as an importer, trailing only the US. We finally conducted scenario modeling by 2030, assuming different progresses on SDG 6 targets. The findings suggest that only the most ambitious progress in both water quality enhancement and efficiency improvement helps to alleviate ∼20 % economic WSR globally. Our findings underscore the necessity for strategies that integrate management of untreated wastewater flows, improved water use efficiency, and diversification of supply chain networks to enhance global economic resilience to water challenges in the future.

Internet-Based Cognitive-Behavioral Therapy for College Students With Anxiety, Depression, Social Anxiety, or Insomnia: Four Single-Group Longitudinal Studies of Archival Commercial Data and Replication of Employee User Study

Background

The growing behavioral health needs of college students have resulted in counseling centers reporting difficulties in meeting student demand.

Objective

This study aims to test the real-world voluntary use by college students of 4 digital, self-directed mental health modules based on a cognitive behavioral therapy clinical model. The findings were also compared with those of employee users.

Methods

Archival operational data from Learn to Live were extracted for student users at 4 colleges and universities in the Midwest region of the United States (N=951). The inclusion criteria were having clinical symptoms at established levels of moderate or higher severity and the use of 2 or more of the 8 lessons of a program within a 6-month period. Unique users in each program included 347 for depression; 325 for stress, anxiety, and worry; 203 for social anxiety; and 76 for insomnia. Paired t tests (two-tailed) compared the average level of change over time on a standardized measure of clinical symptoms appropriate to each program. Cohen d statistical effect sizes were calculated for each program. Potential moderator factors (age, gender, preliminary comprehensive assessment, number of lessons, duration, live coach support, and live teammate support) were tested together in repeated measures analysis of variance models with covariates in the full sample. Follow-up survey data (n=136) were also collected to explore user satisfaction and outcomes. Select data from another study of the same 4 programs by employee users meeting the same criteria (N=707) were examined for comparison.

Results

The percentage of users who improved to a clinical status of no longer being at risk after program use was as follows: stress, anxiety, and worry program (149/325, 45.8%); insomnia program (33/76, 43.4%), depression program (124/347, 35.7%); and social anxiety program (45/203, 22.2%). Significant improvements (all P<.001) over time were found in the mean scores for the clinical measures for each program: stress, anxiety, and worry (t₃₂₄=16.21; d=1.25); insomnia (t₇₅=6.85; d=1.10); depression (t₃₄₆=12.71; d=0.91); and social anxiety (t₂₀₂=8.33; d=0.80). Tests of the moderating factors across programs indicated that greater improvement was strongly associated with the use of more lessons and it also differed by program, by gender (males demonstrated more improvement than females), and by the use of live support (particularly coaching). Analyses of survey data found high satisfaction, improved academic outcomes, and successful integration into the university counseling ecosystem. The operational profile and outcomes of the college students were also similar to those of employee users of the same programs from our other study of employee users. Thus, this study provides a replication.

Conclusions

Self-directed internet-based cognitive behavioral therapy mental health modules are promising as a supplement to traditional in-person counseling services provided by college counseling centers.

Instrument-Assisted Soft-Tissue Mobilization for the Management of Chronic Plantar Heel Pain: A Pilot Study

BACKGROUND

The purpose of this study was to determine feasibility of further investigation of treatment with instrument-assisted soft-tissue mobilization (IASTM), using the Graston technique, compared with conservative care for treatment of chronic plantar heel pain (CPHP).

METHODS

Eleven participants with plantar heel pain lasting 6 weeks to 1 year were randomly assigned to one of two groups, with each group receiving up to eight physical therapy visits. Both groups received the same stretching, exercise, and home program, but the experimental group also received IASTM using the Graston technique. Outcome measures of pain and function were recorded at baseline, after final treatment, and 90 days later. Feasibility of a larger study was determined considering recruitment and retention rates, compliance, successful application of the protocol and estimates of the treatment effect.

RESULTS

Both groups demonstrated improvements in current pain (pain at time of survey), pain with the first step in the morning, and function after final treatment and at 90-day follow up. Medium-to-large effect sizes between groups were noted, and sample size estimates demonstrated a need for at least 42 participants to realize a group difference. A larger-scale study was determined to be feasible with modifications including a larger sample size and higher recruitment rate.

CONCLUSIONS

This pilot study demonstrates that inclusion of IASTM using the Graston technique for CPHP lasting longer than 6 weeks is a feasible intervention warranting further study. Clinically important changes in the IASTM group and moderate-to-large between-group effect sizes suggest that further research is warranted to determine whether these trends are meaningful.

Outcomes among patients receiving in-center, self-care hemodialysis

Modalities of renal replacement therapy are categorized into incenter hemodialysis and home therapies. A subset of hemodialysis patients referred to as in-center self-care hemodialysis (ICSCHD) receive patient training as if they were going home but instead perform their dialysis in-center with minimal staff support. Preliminary data suggests ICSCHD is associated with better outcomes than traditional in-center hemodialysis. We looked at ICSCHD patients initiating maintenance dialysis from April 1, 2011 to March 30, 2014 and compared them at a 1:2 ratio to propensity-score matched controls from surrounding facilities within the same catchment area. The median follow-up was 14 months. Patients on ICSCHD had lower mortality rate (0.02 vs 0.07 per patient year; p <0.05), fewer hospitalization events (0.82 vs. 1.70 per patient year; p = 0.008) and fewer missed treatments (1.1% vs 3.8% of all treatments; p = 0.005) than matched controls. We concluded that patients on ICSCHD had lower mortality rates and fewer hospital days than well-matched controls and spent more time on dialysis and missed fewer treatments. Establishing a facility-wide.

The genetics of an early Neolithic pastoralist from the Zagros, Iran

The agricultural transition profoundly changed human societies. We sequenced and analysed the first genome (1.39x) of an early Neolithic woman from Ganj Dareh, in the Zagros Mountains of Iran, a site with early evidence for an economy based on goat herding, ca. 10,000 BP. We show that Western Iran was inhabited by a population genetically most similar to hunter-gatherers from the Caucasus, but distinct from the Neolithic Anatolian people who later brought food production into Europe. The inhabitants of Ganj Dareh made little direct genetic contribution to modern European populations, suggesting those of the Central Zagros were somewhat isolated from other populations of the Fertile Crescent. Runs of homozygosity are of a similar length to those from Neolithic farmers, and shorter than those of Caucasus and Western Hunter-Gatherers, suggesting that the inhabitants of Ganj Dareh did not undergo the large population bottleneck suffered by their northern neighbours. While some degree of cultural diffusion between Anatolia, Western Iran and other neighbouring regions is possible, the genetic dissimilarity between early Anatolian farmers and the inhabitants of Ganj Dareh supports a model in which Neolithic societies in these areas were distinct.

Managing Disruptive Behavior by Patients and Physicians: A Responsibility of the Dialysis Facility Medical Director

The Centers for Medicare & Medicaid Services' Conditions for Coverage make the medical director of an ESRD facility responsible for all aspects of care, including high-quality health care delivery (e.g., safe, effective, timely, efficient, and patient centered). Because of the high-pressure environment of the dialysis facility, conflicts are common. Conflict frequently occurs when aberrant behaviors disrupt the dialysis facility. Patients, family members, friends, and, less commonly appreciated, nephrology clinicians (i.e., nephrologists and advanced care practitioners) may manifest disruptive behavior. Disruptive behavior in the dialysis facility impairs the ability to deliver high-quality care. Furthermore, disruptive behavior is the leading cause for involuntary discharge (IVD) or involuntary transfer (IVT) of a patient from a facility. IVD usually results in loss of continuity of care, increased emergency department visits, and increased unscheduled, acute dialysis treatments. A sufficient number of IVDs and IVTs also trigger an extensive review of the facility by the regional ESRD Networks, exposing the facility to possible Medicare-imposed sanctions. Medical directors must be equipped to recognize and correct disruptive behavior. Nephrology-based literature and tools exist to help dialysis facility medical directors successfully address and resolve disruptive behavior before medical directors must involuntarily discharge a patient or terminate an attending clinician.

MMP and TIMP temporal gene expression during osteocytogenesis

Osteocytes within bone differentiate from osteoblast precursors which reside in a mineralised extracellular matrix (ECM). Fully differentiated osteocytes are critical for bone development and function but the factors that regulate this differentiation process are unknown. The enzymes primarily responsible for ECM remodelling are matrix metalloproteinases (MMP); however, the expression and role of MMPs during osteocytogenesis is undefined. Here we used MLO-A5 cells to determine the temporal gene expressions of the MMP family and their endogenous inhibitors--tissue inhibitors of metalloproteinases (TIMPs) during osteocytogenesis. RT-qPCR revealed expression of 14 Mmps and 3 Timps in MLO-A5 cells. Mmp2, Mmp23 and Mmp28 were decreased concurrent with mineralisation onset (P < 0.05*). Mmp14 and Mmp19 mRNAs were also significantly increased at day 3 (P < 0.05*) before returning to baseline levels at day 6. Decreased expressions of Timp1, Timp2 and Timp3 mRNA were observed by day 6 compared to day 0 (P < 0.05*). To examine whether these changes are linked to osteocytogenesis, we determined Mmp/Timp mRNA expressions in mineralisation-limited conditions. RT-qPCR revealed that the previously observed decreases in Mmp2, Mmp23 and Mmp28 were not observed in these mineralisation-limited cultures, therefore closely linking these MMPs with osteocyte differentiation. Similarly, we found differential expression of Timp1, Timp2 and Timp3 mRNA in mineralisation-restricted cultures (P < 0.05*). In conclusion, we have identified several members of the MMP/TIMP families as regulators of ECM remodelling necessary for the acquisition of the osteocyte phenotype.

Are block copolymer worms more effective Pickering emulsifiers than block copolymer spheres?

RAFT-mediated polymerisation-induced self-assembly (PISA) is used to prepare six types of amphiphilic block copolymer nanoparticles which were subsequently evaluated as putative Pickering emulsifiers for the stabilisation of n-dodecane-in-water emulsions. It was found that linear poly(glycerol monomethacrylate)-poly(2-hydroxypropyl methacrylate) (PGMA-PHPMA) diblock copolymer spheres and worms do not survive the high shear homogenisation conditions used for emulsification. Stable emulsions are obtained, but the copolymer acts as a polymeric surfactant; individual chains rather than particles are adsorbed at the oil-water interface. Particle dissociation during emulsification is attributed to the weakly hydrophobic character of the PHPMA block. Covalent stabilisation of these copolymer spheres or worms can be readily achieved by addition of ethylene glycol dimethacrylate (EGDMA) during the PISA synthesis. TEM studies confirm that the resulting cross-linked spherical or worm-like nanoparticles survive emulsification and produce genuine Pickering emulsions. Alternatively, stabilisation can be achieved by either replacing or supplementing the PHPMA block with the more hydrophobic poly(benzyl methacrylate) (PBzMA). The resulting linear spheres or worms also survive emulsification and produce stable n-dodecane-in-water Pickering emulsions. The intrinsic advantages of anisotropic worms over isotropic spheres for the preparation of Pickering emulsions are highlighted. The former particles are more strongly adsorbed at similar efficiencies compared to spheres and also enable smaller oil droplets to be produced for a given copolymer concentration. The scalable nature of PISA formulations augurs well for potential applications of anisotropic block copolymer nanoparticles as Pickering emulsifiers.

Integrated renal care: are nephrologists ready for change in renal care delivery models?

The Affordable Care Act is the most visible element of health care reform. However, both before the Affordable Care Act and now with the acceleration since its passage, the Centers for Medicare and Medicaid have been and are testing integrated care models in medicine in general as well as nephrology. The pressures to do so come from the well known increasing costs of health care in the face of a number of clear gaps in quality. The future will likely be more and more integrated care with less and less fee for service. More measurement of quality and the linking of quality measures to payments are also all but certain future elements of the health care economy. Nephrologists need to educate themselves on these trends and be prepared to engage them for the good of the profession and the improvement in care for patients.

Aquaporin-11 control of testicular fertility markers in Syrian hamsters

The present study sought novel changes to the hamster testicular transcriptome during modulation of fertility by well-characterized photoperiodic stimuli. Transition from long days (LD, 14 h light/day) to short days (SD, 10h light/day) triggered testicular regression (61% reduction of testis weight, relative to LD) in SD-sensitive (SD-S) hamsters within 16 weeks. After 22 weeks of SD exposure, a third cohort of hamsters became SD-refractory (SD-R), and exhibited testicular recrudescence (137% testis weight gain, relative to SD-S). Partial interrogation of the testicular transcriptome by annealing-control-primer-modified differential display PCR provided several candidates for regulation of testicular functions. Multiple linear regression modeling indicated the best correlation for aquaporin 11 (Aqp11) with changes in testis weight. Correlations were also strongest for Aqp11 with expression levels of reference cDNAs that control spermatogenesis (Hspa2 and Tnp2), steroidogenesis (Cox2, 3βHsd, and Srebp2), sperm motility (Catsper1, Pgk2, and Tnp2), inflammation (Cox2), and apoptosis (Bax and Bcl2). Moreover, siRNA-mediated knockdown of testicular Aqp11 mRNA and protein reduced Hspa2 and Tnp2 mRNA levels, and it increased 3βHsd mRNA levels. It also reduced mRNA levels for Sept12, which is a testis-specific inducer of spermatogenesis. These results suggest a central role for testicular Aqp11 signaling in the coordinate regulation of crucial components of fertility.

Unification of the voice of nephrology stakeholders

Kidney Care Partners is a coalition made up of representatives from the entire kidney community. Its mission is to ensure that chronic kidney disease patients receive optimal care, lead quality lives, and have ready access to dialysis care. The coalition focuses on consensus building and a community-wide cooperative effort toward developing health policy in the interest of patients. Presently, end-stage renal disease care is underfunded, and factors such as an aging population and an increase in obesity are leading to increased demands on the system. Changes in reimbursement for erythropoiesis-stimulating agents will further challenge this system. Kidney Care Partners is strongly promoting health policy through the support of the Kidney Care Quality and Education Act of 2007 (HR 1193/S 691). Among their activities is the formation of the Kidney Care Quality Initiative in an effort to bring consensus to the development of usable quality measures.

Identifying highly effective psychotherapists in a managed care environment

OBJECTIVE

To investigate the variability and stability of psychotherapists' effectiveness and the implications of this differential effectiveness for quality improvement in a managed care environment.

STUDY DESIGN

Subset archival outcome data for patients receiving behavioral health treatment were divided into 2 time periods to cross-validate the treating therapists' effectiveness. After categorizing the therapists as "highly effective" and "others" during the baseline period, the stability of their individual effectiveness was cross-validated in the remaining time period.

METHODS

Outcomes for 10 812 patients (76.0% adults, 24.0% children and adolescents) treated by 281 therapists were included. Patients initiated treatment between January 1999 and June 2004. Mean residual change scores obtained by multiple regression were used to adjust for differences in case mix among therapists. Raw change scores as well as mean residualized change scores were compared between the 71 psychotherapists identified as highly effective (25%) and those identified as other (remaining 75%).

RESULTS

During the cross-validation period, mean differences in residualized change score between highly effective therapists and others were statistically significant (difference = 2.8; P < .001), which corresponded to an average of 53.3% more change in raw change scores with the highly effective therapists. Results could not be explained by case mix differences in diagnosis, age, sex, intake scores, prior outpatient treatment history, length of treatment, or therapist training/experience.

CONCLUSION

Behavioral health outcomes for a large system of care could be significantly improved by measuring clinical outcomes and referring patients to therapists with superior outcomes.

Implementation of a feedback system in a managed care environment: What are patients teaching us?

Lessons about patient treatment response from a large-scale outcomes management project are summarized. More than 7,000 clinicians contributed outcome data. Overall, the data demonstrated that patients who have clinical levels of psychological distress and impairment showed a relatively rapid response to treatment. Furthermore, although it appears that the duration and intensity of treatment vary widely from case to case, clinicians and patients make sound judgments as to how much and what kind of treatment is appropriate. Results supported the conclusion that the most effective method to manage costs is to ensure that each patient receive effective care. There are large and stable differences in the effectiveness of clinicians, and outcomes can be improved by referring patients to effective clinicians. The data also suggested that patients who had a poor initial response to treatment eventually had positive outcomes, provided that they remained engaged in treatment. This finding suggests that outcomes can be improved by identifying at-risk patients and proactively keeping them engaged in treatment.

Improving suicide risk assessment in a managed-care environment

This article describes the quality improvement intervention of a managed behavioral healthcare company to improve the quality of suicide risk assessments by its panel of providers. At-risk cases are identified by the patient's self-reported high frequency of suicidal ideation on a standardized outcome measure. Clinicians also assess severity of suicidal ideation based on clinical interviews. The clinician's assessment is identified as probably erroneous if the patient report indicates a high frequency of suicidal ideation and the clinicians assessment of suicidal ideation is none. The article describes the methods used to encourage clinicians to utilize information from the patient self-report measure as part of the clinical assessment. Probable suicidal ideation assessment errors were subsequently reduced by 29% over a 1-year period of administration.

Improving Suicide Risk Assessment in a Managed-Care Environment

Summary: This article describes the quality improvement intervention of a managed behavioral healthcare company to improve the quality of suicide risk assessments by its panel of providers. At-risk cases are identified by the patient's self-reported high frequency of suicidal ideation on a standardized outcome measure. Clinicians also assess severity of suicidal ideation based on clinical interviews. The clinician's assessment is identified as probably erroneous if the patient report indicates a high frequency of suicidal ideation and the clinicians assessment of suicidal ideation is none. The article describes the methods used to encourage clinicians to utilize information from the patient self-report measure as part of the clinical assessment. Probable suicidal ideation assessment errors were subsequently reduced by 29% over a 1-year period of administration.

A ten-year review of the validity and clinical utility of depression screening

OBJECTIVE

Use of depression screening instruments in primary care is controversial. The authors reviewed research studies published since the development of national practice guidelines to determine whether new evidence might favor screening. The review focused on evidence-related validity and clinical utility of depression screening instruments.

METHODS

Silver Platter MEDLINE was searched for English-language studies of depression screening instruments published between 1986 and 1995. Studies were classified by type--reviews of studies, outcome studies, validation studies.

RESULTS AND CONCLUSIONS

Fifty-nine studies met criteria for review. Validation studies were the most frequent type (39 studies) and were subclassified according to population, type of comparison, and analytical method. These studies documented the validity of screening instruments compared with formal criteria and demonstrated consistently better performance for systematic approaches compared with clinical impressions. Thirteen studies were reviews; those reviewing evidence for effectiveness disagreed in their conclusions. Only seven outcome studies related to depression screening instruments were found, and none showed measurable benefit in a screened population. Several studies showed that very brief instruments performed about as well as longer, well-validated questionnaires for screening in general populations.

The magnitude of metabolic acidosis is dependent on differences in bicarbonate assays

Metabolic acidosis has been recently recognized as an important comorbid event in the high mortality rates seen in patients with end-stage renal disease. The recognition of hypobicarbonatemia is dependent on a reliable assay for total carbon dioxide (TCO2). It is common practice for dialysis facilities to send blood samples for testing to remote laboratories, which may assay bicarbonate differently than the local hospital. We noted that serum bicarbonate concentrations from blood samples sent to our reference laboratory were significantly lower (4 mEq/L) compared with blood samples sent to our local laboratory. Blood samples were assayed for TCO2 using an enzymatic technique (in the reference laboratory) and direct measurement using an electrode (in the local laboratory). The blood test results for TCO2 sent to the reference laboratory (18.7 +/- 0.8 mEq/L) were significantly lower than samples assayed in our local laboratory (22.2 +/- 0.7 mEq/L). In conclusion, recognition of the differences in assays used in the laboratory for routine bicarbonate measurements is important in defining the magnitude of metabolic acidosis and in helping to dictate appropriate therapy.

Early English steroid history

Following the revelation of the presence of vitamin D in fish liver oils and of estrogenic hormones in pregnancy urine in the 1920s, active interest in the steroids began in England. Most of this interest originated from the studies of Ian Heilbron at Liverpool and of Otto Rosenheim at the National Institute for Medical Research in London.

A pragmatist's approach to pathology costing: the Welsh Datatree project

The Datatree costing project in Wales has provided the Welsh pathology laboratories with a standard costing package that allows pathologists to understand how their own laboratory's test costs are compiled. The software provides answers to the question "what if? ..." and shows instantly the effect of salary or consumable cost alterations. Resource management at a laboratory level is enhanced by a greater knowledge of costs, particularly in relation to volumes of work. Perhaps this is one of the stepping-stones across the river to the "open market." In the United Kingdom NHS any information of this kind must be regarded as invaluable.

Attitudes of paediatricians to HIV and hepatitis B virus infection

There is a recent upsurge of interest among health care professionals regarding the risk of accidental occupational exposure to HIV virus. We evaluated knowledge of virus carriage prevalence, needlestick injuries, venepuncture practices, and glove use among paediatricians in Wales and South West Regional Health Authorities. We also attempted to evaluate hepatitis B immunisation uptake in this group. Paediatricians have traditionally been considered a low risk group in the context of accidental occupational exposure to these viruses. We targeted a four point questionnaire at 221 paediatricians. Results suggested that despite recent increasing concern about these viruses, that is reflected in the amount of medical literature recently published, and the issuing of Department of Health guidelines on venepuncture, knowledge of prevalence of HIV and hepatitis B carriage rates, and hence assessment of risk magnitude, was surprisingly poor. Safe venepuncture practices were not widely used. In the 12 months before receiving the questionnaire 55% had suffered a needlestick injury with only 10% reporting the fact. Hepatitis B immunisation uptake was highest in the junior grades (but this does not necessarily mean those at greatest risk). There were many inconsistencies between the clinicians' perceptions of risk and their practices. As the virus attains a firm hold in the heterosexual population paediatricians by virtue of the nature of venepuncture in children will almost certainly see their risk of acquiring HIV/hepatis B viruses secondary to accidental occupational exposure increase over the next decade. Without an improvement in current knowledge of carriage prevalence in high risk areas and alteration in venepuncture practices/hepatitis B immunisation uptake some will unfortunately, though avoidably, contract these bloodborne viral infections.

Occupational medicine residency training programs. The role occupational health nurses play

An experienced occupational health nurse with suitable academic qualifications is able to assist in providing a well-rounded education and teaching physicians to be effective members of occupational health teams. Nurses are involved in teaching occupational health to physicians in the academic and practicum phases of occupational medicine residency training programs. However, the involvement of nurses in training physicians is inconsistent among the accredited residencies. Most of the nurses involved in teaching occupational health to physicians are at least master's degree prepared. Nurses are involved in the didactic, clinical, and administrative components of the training programs. Though nurses are involved in residency training programs to an extent, the lack of consistent involvement limits the diversity of points of view and fosters an imbalance in the training of occupational medicine residents.

Twice daily versus four times daily treatment with beclomethasone dipropionate in the control of mild childhood asthma

The effects of controlling childhood asthma of the same daily dose (400 micrograms) of beclomethasone dipropionate, given in two or four equal divided doses from a metered aerosol, were compared in a double blind crossover study. Thirty one children aged 6-14 years completed the study. They had previously been shown to need beclomethasone by showing either symptoms or reduced peak flow when the treatment was withdrawn. They recorded their daytime and night time symptoms on a visual analogue scale and their morning and evening peak expiratory flow (PEF), and recorded their symptomatic use of bronchodilator aerosols. Spirometry was performed at the end of each treatment period. Control of asthma was good on both regimens. There were small differences in both objective and subjective measurements in favour of the four times daily regimen, but none reached statistical significance, apart from patients' assessment of daytime wheeze (p less than 0.05). In particular, the differences in the results of lung function tests were very small. Compliance was better for morning and evening doses. These results suggest that beclomethasone given as 200 micrograms twice daily is effective in controlling mild childhood asthma. It may be preferable to 100 micrograms four times daily because of better compliance and because it is unnecessary to take medication to school.

Prostaglandins inhibit renal ammoniagenesis in the rat

We describe the inhibitory effect of prostaglandins (PGs) on in vivo rat renal ammonia synthesis. The influence of systemic pH upon urinary PG excretion and ammoniagenesis was also investigated. Finally, PG production by incubated rat renal cortical slices was suppressed to investigate the PG-ammonia interplay in the absence of changes in renal blood flow, glomerular filtration rate, ambient electrolyte concentrations or extrarenal hormonal factors. In vivo ammonia synthesis doubled and PG excretion fell by 44% in normal rats, after intravenous administration of 1 mg/kg of meclofenamate. Higher doses of meclofenamate further augmented ammonia production and further reduced PG excretion. PG depletion was also associated with an increase in fractional excretion of ammonia (FENH3) that was independent of changes in urine flow rate or pH. Acute metabolic acidosis (AMA) increased total ammonia synthesis but also stimulated PG production. Administration of meclofenamate to rats with mild AMA markedly reduced urinary PG excretion, further augmented ammonia synthesis, and significantly increased the FENH3. Inhibition of stimulated PG synthesis during severe AMA did not increase ammoniagenesis or FENH3. Acute metabolic alkalosis did not alter production of PGs or ammonia, but reduced the FENH3 by 42%. Meclofenamate nearly normalized the FENH3 but stimulated synthesis to a lesser degree than was seen in nonalkalotic rats that received meclofenamate. Inhibition of PG synthesis in incubated rat renal cortical slices also stimulated ammoniagenesis. Conversely, stimulation of PG synthesis decreased ammonia production and acidification of the incubation medium increased prostaglandin F2 alpha production. Thus, in vitro findings support the in vivo results. We conclude that PGs inhibit ammonia synthesis in normal rats and in those undergoing mild AMA. Severe acidosis overrides this inhibitory effect of PGs, whereas metabolic alkalosis suppresses the stimulatory effect of PG synthesis inhibition.

Diagnostic strategies in disorders of fluid, electrolyte and acid-base homeostasis

Our understanding of the physiology and biochemistry of acid-base and fluid-electrolyte regulations has greatly expanded in recent years. Key physiologic principles have emerged that now permit rational diagnosis and therapy of clinical disorders of serum electrolyte concentration. This paper describes diagnostic strategies based upon these principles. The etiology of the myriad factors in hyponatremia is best derived by first measuring serum tonicity and then assessing extracellular fluid volume. The hyper-, iso- and hypotonic hyponatremia are defined, and the hypotonic group is subclassified into hypo-, iso- and hyper volemic forms. The hypernatremias are best categorized by their state of volume expansion. Classification into the hypo-, hyper- and isovolemic hypernatremias simplifies their diagnosis. Metabolic acidoses are classified in terms of the anion gap. Clinical and chemical aspects of increased and normal anion gap acidoses are described. Metabolic alkaloses require a source of new bicarbonate and its retention by the kidney. The means by which new alkali is synthesized and urinary loss prevented serve to effectively classify the alkaloses. Hypokalemic syndromes are defined in terms of associated changes in body potassium. The potassium-depleted states are further subclassified by whether normotension or hypertension is associated. Hyperkalemia is produced by redistribution of cellular and extracellular potassium or by increased body potassium. Defects in the renin-angiotensin-aldosterone-distal renal tubule effector arm usually underlie hyperkalemic states, which are than classified in terms of this regulatory hormonal cascade. Classifications for disordered serum concentrations of calcium, magnesium, phosphorus and uric acid are presented. Hormonal, metabolic and renal regulatory factors form the basis for an organized approach to these disorders.

A four-year follow-up of schoolgirls with untreated covert bacteriuria: bacteriological aspects

In 75 schoolgirls aged 5-11 with untreated covert coliform bacteriuria who were followed up to 4 years, infection cleared in 16 (21%), cleared and recurred in 37 (50%) and persisted in 22 (29%). Clearance of bacteriuria was significantly (P less than .05) more frequent in girls with normal radiological findings than in those with abnormal findings. In 31 (59%) of the 53 girls in whom bacteriuria cleared spontaneously, the urine became sterile within the first year after the discovery of the bacteriuria. Spontaneous clearance of bacteriuria was preceded by an increase of the sensitivity of the urinary pathogens to the cidal effect of human serum. Seven (10%) of the 75 untreated bacteriuric girls had shown progression of kidney damage (progression of scarring in 4 and failure of kidney growth in 3). In all of these 7 girls vesico-ureteric reflux (VUR) was present and bacteriuria was persistent, but in 6 of them from one to three changes in the serotype of Esch. coli or bacterial species were noted during follow-up. These observations suggest that changes in bacterial flora may be a risk factor in the progression of kidney damage in girls with urinary tract infection and VUR.