Properties of flocs produced by water treatment coagulants

Hydrolyzing coagulants are extensively used in water and wastewater treatment, often under conditions where hydroxide precipitation is important, giving "sweep flocculation". Pre-hydrolyzed coagulants, such as polyaluminium chloride (PACl) are also widely used and have several advantages over traditional additives, such as aluminium sulfate. Their action is usually discussed in terms of cationic species and charge neutralization. However, precipitation may also be important and this aspect has not been considered in detail. The present work has compared the action of alum and three commercial PACl products on model clay suspensions. The conventional jar test procedure has been used, along with measurements of settled floc volume and dynamic monitoring of floc formation and break-up by an optical technique. The latter method gives very useful information on the nature of the flocs produced and their response to different shear conditions. It is clear from the results that the PACl products form larger and stronger flocs than alum. With all coagulants floc breakage appears to be essentially irreversible. Sediment volumes are slightly lower for flocs produced by PACl than by alum, but the value is proportional to the dosage in all cases.

Novel TSHR germline mutation (Met463Val) masquerading as Graves' disease in a large Welsh kindred with hyperthyroidism

Hereditary nonautoimmune hyperthyroidism is caused by activating germline mutations in the thyrotropin (TSH) receptor (TSHR) gene. We describe an extended Welsh kindred with toxic thyroid hyperplasia affecting 8 family members in three generations and a history consistent with thyrotoxicosis in a further three generations now deceased. A novel heterozygous germline mutation (ATG --> GTG; Met463Val) was identified in the second membrane spanning TSHR region in 6 relatives with thyrotoxicosis and goiter and absence of TSHR antibodies. Screening of 5 additional family members led to the identification of 2 siblings with the mutation, who were asymptomatic at the time, although subsequent thyroid function tests in these children showed suppressed serum TSH and increased serum free triiodothyronine (FT3) and free thyroxine (FT4) concentrations. Functional studies of the novel TSHR germline mutation demonstrated a constitutive activation of the cAMP pathway, which in the thyroid controls both thyroid hormone production and stimulation of thyroid growth. The molecular diagnosis in this family has clinical implications: genetic counseling is required, and primary thyroid ablation should be advocated as the preferred treatment in the patients with the constitutively activating TSHR germline mutation.

An outbreak of ciguatera fish poisoning in Victoria

An outbreak of ciguatera fish poisoning in outer Melbourne in September 1997 was traced to a 16.2 kg Maori Wrasse fish imported into Victoria from Trunk Reef in Queensland. The outbreak involved 46 individuals attending a banquet at an Asian restaurant at which four different dishes prepared from the flesh and viscera of the fish were offered. In all 30 individuals consumed at least one of these dishes and all reported one or more symptoms, in the main gastrointestinal and/or in 18 cases neurological. Seventeen cases were seen in four different hospitals and nine were treated with parenteral mannitol therapy. Nine of 18 cases were still symptomatic 10 weeks after the episode. Education of Asian restaurateurs and the wider community about the risks of ciguatera fish poisoning was undertaken.

No association between androgen or vitamin D receptor gene polymorphisms and risk of breast cancer

Endogenous hormone exposure is known to alter breast cancer susceptibility and genes responsive to such hormones are plausible candidates for predisposition genes. We have examined polymorphisms in genes for two members of the nuclear receptor superfamily which are expressed in breast tissue and known to moderate rates of cell proliferation in a case-control association study: the androgen receptor (AR) and the vitamin D receptor (VDR). We have used two series of Caucasian female breast cancer cases, one incident and one prevalent, and compared both with two sets of matched controls from the East Anglian region of Britain. Since the results are similar in the two series we have combined them. The AR poly[Gly](n) and poly[Gln](n) tracts were genotyped in a total of 508 female breast cancer cases and 426 controls. The VDR TaqI polymorphism was analysed in 951 cases and 627 controls drawn from the same population series. There were no significant differences between cases and controls for either the AR or VDR polymorphisms. Compared with individuals with two short alleles (<22 repeats) of the AR poly[Gln](n) tract, the odds ratios and 95% confidence intervals (95% CI) for individuals with one or two long alleles were 0.82 (95% CI 0.62-1.09) and 1.31 (95% CI 0.87-1.97), respectively. Heterozygotes and homozygotes for the VDR TaqI cutting site had odds ratios of 1.01 (95% CI 0.81-1.27) and 0.97 (95% CI 0.71-1.32), respectively. None of the AR or VDR polymorphisms investigated has a major effect on risk of breast cancer in the British population.

Evaluation of a novel dry latex preparation for demonstration of infectious mononucleosis heterophile antibody in comparison with three established tests

A new, dried antigen-coated latex preparation for the demonstration of infectious mononucleosis (IM) heterophile antibody (Dryspot IM kit; Oxoid, Ltd., Basingstoke, Hampshire, United Kingdom) was compared with the IM kit (a liquid latex reagent from the same source), an immunoassay (ImmunoCard Mono; Meridian Diagnostics), and an absorption test (Monospot; Meridian Diagnostics). The latter was used as a standard for initial statistical comparisons. Discrepancies were resolved by using Epstein-Barr virus serology. Of the 328 routine samples tested, 77 were positive and 222 were negative by all IM heterophile antibody-based kits. Twenty-nine samples gave discrepant results. Following resolution of discrepant results, the sensitivity and specificity values for the IM Dryspot kit were 87.0 and 98.7%, those for the Oxoid liquid latex IM kit were 83.0 and 99.6%, and those for the ImmunoCard Mono immunoassay were 85.0 and 100.0%, respectively. The evaluation shows that the Dryspot kit, which is uniquely straightforward to use and may be stored at room temperature, is comparable in performance to other rapid heterophile tests for the confirmation of IM.

Examination for cardiac malformations at six weeks of age

AIM

To attempt to define the prevalence and significance of murmurs detected on routine clinical examination at six to eight weeks.

METHODS

A retrospective review of the results of routine clinical examination of a cohort of 6 to 8 week old babies resident in Newcastle upon Tyne, was carried out in two 12 month periods. All cardiac defects diagnosed in infancy in the same cohort were ascertained.

RESULTS

7132 babies were eligible for routine examination; 83% of these were examined. Murmurs were heard in 47 of 5395 babies and in 11 of 25 referred for evaluation congenital heart disease was found. The six to eight week examination led to diagnosis of 11 of 35 cases (31%) of congenital heart disease in the study population.

CONCLUSIONS

Nearly one baby in 100 had a murmur on routine examination at six to eight weeks. Nearly half of those with murmurs who were referred had a structural cardiovascular malformation.

Comparison between enzyme-linked immunosorbent assay and cytotoxic cross-match procedures for detecting IgG anti-donor antibodies

BACKGROUND

Disadvantages inherent to complement-dependent cytotoxicity cross-match (CDC XM) methods are the requirements for complement and viable target cells, detection of antibodies (Abs) against non-HLA antigens, and subjective scoring. Cross-Stat (SangStat Medical Corp., Menlo Park, CA), a recently developed enzyme-linked immunosorbent assay XM procedure for the detection of IgG anti-donor HLA Abs, is theoretically devoid of these flaws.

METHODS

We compared results of Cross-Stat and our standard anti-human globulin (AHG)-enhanced CDC XM procedure on 524 sera from 230 transplant candidates, which were evaluated against 51 cadaveric donors.

RESULTS

There was a significant correlation between AHG-CDC IgG XM and Cross-Stat results (P<0.001). For false negative sera, repeat AHG-CDC IgG XMs were still positive after platelet absorption, indicating that the Abs present were either non-HLA Abs or anti-HLA class II. Flow cytometry testing of false positive sera usually (42/62) substantiated Cross-Stat results, indicating that the discrepancy with AHG-CDC IgG XM is caused by greater sensitivity of Cross-Stat. Relative to the AHG-CDC XM, the sensitivity of Cross-Stat was 100%, the specificity was 93%, the positive predictive value was 73%, and the negative predictive value was 100%. A technical shortcoming of the Cross-Stat assay is that the frequency of indeterminate samples in the assays was 15%. Among 49 Cross-Stat negative vs. 13 Cross-Stat positive primary cadaveric renal allograft recipients (all AHG-CDC IgG-XM negative), there was no statistical difference in overall graft survival.

CONCLUSION

Given the important theoretical advantages of enzyme-linked immunosorbent assay-based XM methods over the CDC XM, however, further testing of the clinical relevance of the Cross-Stat is warranted.

Evaluating therapist competency and adherence to behavioral family management with bipolar patients

The present study assessed fidelity to the behavioral family management (BFM) model for treating bipolar disorder patients and their families. The BFM Therapist Competency/Adherence Scale (BFM-TCAS) was developed to evaluate clinicians' competency and adherence to BFM, as outlined by Miklowitz' (1989) BFM Manual for use with bipolar patients. Therapist competency and treatment adherence was also evaluated with regard to two family characteristics: overall level of family difficulty and family expressed emotion (EE) status. The BFM-TCAS was used to code 78 videotaped sessions of 26 families with a bipolar member, selected from a larger treatment study of bipolar disorder patients. The findings suggest that, overall, clinicians adhered closely to the BFM manual. Specific areas in which there was high competency and treatment adherence were (a) skill in conveying factual information about bipolar illness, (b) establishment of a therapeutic environment, and (c) ability to take command of therapy sessions. The one area in which there was less competency and relatively weak adherence to the manual was the use of between-session homework assignments to assist families in mastering the BFM exercises. Results of this study also suggest that, for the most part, therapist competency and adherence ratings were not related to overall level of difficulty or to family EE status.

Salmonella in Victoria, 1997: the story so far

The Infectious Diseases Unit of the Department of Human Services, Victoria, reported an increased incidence of Salmonella infections in early 1997. To 21 April 1997, 944 notifications had been received, passing the previous year's total of 915. Five outbreaks of five separate serovars have been investigated and traced to their sources. The outbreaks, their sources and the control measures undertaken are described. Further clusters of other Salmonella serovars are being investigated.

Extracts of several letters sent to the Publisher from Edinburg, by the Learn'd Mr. James Gregory, to whom they were written by that intelligent knight Sir George Makenzy from Tarbut

1. The wind here, on the 21 th of Decemb . last, was extraordinary: it broke a Standard-stone, that stood as an Obelisk near an Old Chuch; which stone was about 12 foot high, 5 foot broad, and near 2 foot thick.

Physician activism. You can help Stop America's Violence Everywhere

Physicians are one group of people who don't need to be reminded of the devastating effect of violence on our families, our health care system, and our society. That's why you are invited to help the county, state, and national medical society alliances SAVE Today...Stop America's Violence Everywhere. Governor Engler will sign a proclamation declaring October 9, 1996 as SAVE Today, a national day to Stop America's Violence Everywhere.

Reduction in dissociation due to aging and cognitive deficit

Our objective was to investigate whether dissociative experiences occur less frequently in older psychiatric patients than in younger adult patients, and to examine the role of cognitive deficits in the frequency of dissociative events. Fifty-two outpatients 60 years and older were administered the Dissociative Experiences Scale (DES) and the Mini-Mental State Exam (MMSE). Their scores were compared with those of 50 outpatients 35 to 55 years old. Each group included patients sampled from the Mental Health Center (MHC) and University Medical Center clinics. Older patients showed significantly lower DES and MMSE median scores than younger patients. Cognitive deficit reflected by reduced MMSE scores also was associated with reduced DES scores for younger and older patients. Older patients with little or no cognitive deficit continued to show reduced DES scores. Decreases in dissociativity continue well beyond the fourth decade and do not rely on age-related cognitive deficit. Factors related to the aging process seem to mediate reductions in dissociativity independent of reductions mediated by cognitive deficit. The use of the DES for screening without adjusting for age and cognitive status is questioned.

Membrane/microtubule tip attachment complexes (TACs) allow the assembly dynamics of plus ends to push and pull membranes into tubulovesicular networks in interphase Xenopus egg extracts

We discovered by using high resolution video microscopy, that membranes become attached selectively to the growing plus ends of microtubules by membrane/microtubule tip attachment complexes (TACs) in interphase-arrested, undiluted, Xenopus egg extracts. Persistent plus end growth of stationary microtubules pushed the membranes into thin tubules and dragged them through the cytoplasm at the approximately 20 microns/min velocity typical of free plus ends. Membrane tubules also remained attached to plus ends when they switched to the shortening phase of dynamic instability at velocities typical of free ends, 50-60 microns/min. Over time, the membrane tubules contacted and fused with one another along their lengths, forming a polygonal network much like the distribution of ER in cells. Several components of the membrane networks formed by TACs were identified as ER by immunofluorescent staining using antibodies to ER-resident proteins. TAC motility was not inhibited by known inhibitors of microtubule motor activity, including 5 mM AMP-PNP, 250 microM orthovanadate, and ATP depletion. These results show that membrane/microtubule TACs enable polymerizing ends to push and depolymerizing ends to pull membranes into thin tubular extensions and networks at fast velocities.

Localization of the angiotensin II and its receptor subtype expression in human endometrium and identification of a novel high-affinity angiotensin II binding site

Angiotensin (ANG) II is not only a potent vasoconstrictor but may also be involved in the regeneration of new blood vessels. In proliferative endometrium, ANG II-like immunoreactivity was detected in glandular epithelium and stroma with negligible staining around the vascular endothelium. In contrast, in secretory endometrium intense immunostaining was seen in the perivascular stromal cells around the endometrial spiral arterioles with negligible staining of the other cell types. Quantitative receptor autoradiography using the nonselective radioligand [125I]-ANG II and subtype selective competing compounds showed that endometrium contained predominantly AT2 receptors, with relatively low expression of AT1 receptors and a novel non-AT1/non-AT2 angiotensin II recognition site that was insensitive to AT1 or AT2 selective ligands. Levels of specific [125I]-ANG II receptor binding displayed cyclic changes during the menstrual cycle, reaching a maximum in early secretory endometrium and then decreasing in mid to late secretory endometrium to levels seen in early to mid proliferative endometrium. In situ hybridization showed AT1 receptor mRNA expression in the glands and in the endometrial blood vessels. The cyclic changes in ANG II-like immunoreactivity together with expression of both the known and the novel AT receptor subtypes imply that this octopeptide may play a dual role both in the control of the uterine vascular bed and also in the regeneration of the endometrium after endometrial shedding, acting as an angiogenic and mitogenic mediator.

Energy expenditure in children aged 1.5 to 4.5 years: a comparison with current recommendations for energy intake

OBJECTIVE

To compare measurements of total energy expenditure in children aged 1.5-4.5 years with current recommendations for energy intake.

DESIGN

Total energy expenditure was measured using the doubly labelled water technique and compared with 1991 UK recommendations for energy intake.

SETTING

Community-based study in East Anglia and South East England.

SUBJECTS

Ninety-three children aged 1.5-4.5 years recruited. Results available on 81 children.

RESULTS

Mean values for total energy expenditure for the boys were 359, 341 and 327 kJ/kg in the age groups 1.5-2.5, 2.5-3.5 and 3.5-4.5 years respectively. In the girls, mean values for total energy expenditure were 347, 317 and 310 kJ/kg in the age groups 1.5-2.5, 2.5-3.5 and 3.5-4.5 respectively. These values were approximately 12% and 10% below current recommendations for energy intake in girls and boys respectively.

CONCLUSION

These data add to the growing literature that indicate that energy expenditure in young children is significantly below previous estimates. Secular changes in habitual levels of physical activity might be responsible for reduced levels of physical activity.

Naming notes: transitions from free text to structured entry

To practice medicine in the near future, health care providers in the USA need an information infrastructure they do not yet have. We offer a contribution from social science research to discussions of current medical records practices and how health care activity systems may be transformed by the advent of electronic health records. The goal of the paper is to set forth a framework that connects over-arching questions concerning medical informatics systems development with the practical, cultural and conceptual issues involved in transitions from handwritten and other free text documentation to structured entry of medical records to build patient profiles. The research is broadly framed by an interest in how reciprocal modifications of the design and use of an electronic health record are negotiated in an iterative prototyping project. It is conducted as part of a complex multi-disciplinary research and development effort to create an electronic health record prototype for use in the integrated health care delivery environment of the Southern California Kaiser Permanente Medical Care Program.

Evaluating the impact of structured text and templates in ambulatory nursing

This evaluation looks at the use of templates for entering structured text nursing notes that generate both a legal text note that is the chart record and an underlying coded form of the note to support analysis and research. This study reflects the first phase of a prototype project of an integrated, computerized health record. Templates are notes that have been prewritten using a standard clinical vocabulary. Templates can be used as the basis of a new clinical note and can be either signed unchanged or modified to represent variations in clinical presentation. The prototype setting is a Primary Care clinic where both physicians and nurses are using the computer to enter clinical notes. In the prototype clinic team, nursing utilized the CPR for 100% of all documentation from day one. Use of templates was found to be the most frequent method of initiating a note.