A health risk assessment of reclaimed municipal wastewater for industrial and miscellaneous use.

The study evaluated the safety of reclaimed water using health risk assessment and biotoxicity tests. The reclaimed water was produced from reverse osmosis and used in industrial and miscellaneous purposes. The health risk assessment was conducted based on the concentrations of detectable pollutants in reclaimed water in a hypothetical scenario. The estimated carcinogenic and non-carcinogenic risks are lower than the generally accepted level. Biotoxicity evaluation included three genotoxicity tests, a chronic toxicity test using medaka fishes, and a subchronic toxicity test using mice. The reclaimed water is not genetically toxic, and does not cause significant chronic effects on these model organisms. These results confirm the safety of using reclaimed water from municipal wastewater treatment plants.

Anaerobic digestion of polyelectrolyte flocculated waste activated sludge.

This work examined how adding one of three polyelectrolyte flocculants (T3052: cationic, T2000: non-ionic, and T1052: anionic) affected the anaerobic digestion of wastewater sludge. Methane production, floc characteristics (morphology and zeta-potential) and process parameters (soluble chemical oxygen demands (SCODs) and reductive potentials) were monitored along the digestion tests. The digestion rates of T2000- and T1052-conditioned sludge resembled that for original sludge. The T3052-flocculated sludge generated methane at a higher rate during the first 6 days of digestion than did the original one. In the following stage, the digestion rate of sludge flocculated with T3052 at dosage exceeding 15 g/kg dried solids declined. For example, at 40 days of digestion the methane production amounts for original, 15 g/kg DS flocculated, and 40 g/kg flocculated sludge were of 136, 105, and 85 g/kg DS, respectively. The role of flocculants could change in different stages of digestion. The dosed polymers had no apparent toxicity to the inoculum used. The changes in SCOD, adenosintriphosphate concentrations, oxidative and reductive potential, and zeta-potentials did not correlate with the noted hindered digestion for T3052-conditioned sludge. Microphotographic observation revealed that the flocs of T3052-conditioned sludge were not only of a large size, but also were resistant to structural deterioration during digestion. Therefore, mass transfer resistance was proposed to account for the hindered digestion efficiency observed for T3052-conditioned sludge.

Recall of preoperative anaesthesia information in Hong Kong Chinese patients.

OBJECTIVE: To evaluate the ability of patients to recall information provided during a preoperative visit. DESIGN: Qualitative study. SETTING: Regional hospital, Hong Kong. PATIENTS: Sixty patients scheduled for elective surgery under general anaesthesia or central neuro-axial block. MAIN OUTCOME MEASURES: Satisfactory recall of preoperative information, defined as the ability to remember at least 75% of adverse effects described. RESULTS: Fifty-nine (98.3%) patients were satisfied with the preoperative information. Forty-two (70%) patients rated anaesthetic complications as important. At the interview on the day of the operation, 57 (95%) patients had satisfactory recall of the information provided. Eighty-five percent of patients remembered that the information was provided by an anaesthesiologist. After the operation, of those who experienced adverse effects, 48 (96%) patients remembered being told to anticipate the adverse anaesthetic event. Univariate analysis found that age, sex, education level, occupation, and the modality of anaesthesia did not affect patient recall of preoperative information on the day of surgery or 1 day postsurgery. CONCLUSION. There was satisfactory recall of preoperative information by the majority of patients in the study. Most patients expressed satisfaction with the information provided.

Using ATP bioluminescence technique for monitoring microbial activity in sludge.

This study demonstrates, for the first time, that the presence of suspended solids in waste-activated sludge interferes with adenosine triphosphate (ATP) bioluminescence tests. The sludge subject to acid/alkaline treatment represented the test sample. Without consideration of the effect of solid concentrations, one would erroneously estimate the density levels of heterotrophic bacteria in the sludge using ATP data. A light blockage model was proposed to evaluate the luminescence reading without the interference of suspended solids.

Tracheal intubation using suspension laryngoscopy in an infant with Goldenhar's syndrome.

We present a case of a ten-month-old boy with Goldenhar's syndrome and significant retrognathia in whom a tracheostomy was performed to relieve upper airway obstruction. Tracheal intubation was facilitated by direct suspension laryngoscopy using a slotted rigid laryngoscope. We propose this technique as an alternative method for tracheal intubation in infants and young children with a difficult airway. The management of the difficult airway in children with Goldenhar's syndrome is discussed.

Dolichoectasia of the intracranial arteries in patients with first ischemic stroke: a population-based study.

OBJECTIVE: The objective of this study was to estimate the frequency of intracranial arterial dolichoectasia among patients with first ischemic stroke and to compare clinical characteristics, survival, and recurrence in those with and without the abnormality. BACKGROUND: Dolichoectasia may cause cerebral infarction by thrombosis, embolism, stenosis, or occlusion of deep penetrating arteries. METHODS: The chi-square, Fisher's exact, and logrank tests were used to compare clinical characteristics, survival, and recurrence for patients with and without dolichoectasia among the 387 residents of Rochester, MN, who had brain CT or MRI for first cerebral infarction from 1985 through 1989. RESULTS: Twelve patients (3.1%) had dolichoectasia. Patients with dolichoectasia were more likely to have had stroke fitting a clinical and radiographic pattern of lacunar infarction than those without (42% and 17% respectively; p=0.04). Dolichoectasia was detected in the vertebrobasilar system in eight patients (66.7%), in the carotid system in two patients (16.7%), and in both circulatory systems in two patients (16.7%). There were no significant differences in the following characteristics among those with and without dolichoectasia: age, sex, hypertension, diabetes, smoking, and preceding transient ischemic attack. Patients with dolichoectasia had better survival (relative risk [RR] for death, 0.26; p=0.04) after first cerebral infarction but higher rates of stroke recurrence (RR, 2.4; p=0.02). CONCLUSIONS: Dolichoectasia is detected in 38 of patients with first cerebral infarction and is associated with better survival but higher rates of stroke recurrence.

Patent foramen ovale in patients with cerebral infarction. A transesophageal echocardiographic study.

OBJECTIVES: To determine the frequency of patent foramen ovale (PFO) among various subtypes of cerebral infarction. To determine whether any historical or clinical characteristics predict the presence or absence of PFO in these patients. DESIGN: Comorbidity and infarct subtype study. SETTING: Referral-based study. PATIENTS: One hundred sixteen patients with cerebral infarction consecutively referred for transesophageal echocardiography during a 6-month period. MAIN OUTCOME MEASURES: Infarct subtype classification was made using a clinical and radiographic diagnostic rubric similar to that used by the Stroke Data Bank of the National Institute of Neurological Diseases and Stroke. The frequency of various risk factors and clinical characteristics in patients with and in those without PFO and the frequency of PFO in patients with various infarct subtypes were compared (chi 2 or Fisher exact tests). RESULTS: Patent foramen ovale was detected in 37 patients (32%). Mean age was similar in those with (60 years) and those without (64 years) PFO. Patent foramen ovale was more frequent among men (39%) than women (20%, P = .03). Patients with PFO had a lower frequency of atrial fibrillation, diabetes mellitus, hypertension, and peripheral vascular disease compared with those without PFO. There was no difference in frequency of the following characteristics in patients with PFO compared with those without PFO: pulmonary embolus, chronic obstructive pulmonary disease, pulmonary hypertension, peripheral embolism, prior cerebral infarction, nosocomial cerebral infarction, Valsalva maneuver at the same time of cerebral infarction, recent surgery, or hemorrhagic transformation of cerebral infarction. Patent foramen ovale was found in 22 (40%) of 55 patients with infarcts of uncertain cause and in 15 (25%) of 61 with infarcts of known cause (cardioembolic, 21%; large vessel atherostenosis, 25%; lacune, 40%) (P = .08). When the analysis was restricted to patients who underwent Valsalva maneuver, PFO with right to left or bidirectional shunt was found in 19 (50%) of 38 patients with infarcts of uncertain cause and in 6 (20%) of 30 with infarcts of known cause (P = .01). CONCLUSION: Although PFO was overrepresented in patients with infarcts of uncertain in our and other studies, it has a high frequency among patients with cerebral infarction of all types. The relation between PFO and stroke requires further study.

Modular design of the Enterococcus hirae muramidase-2 and Streptococcus faecalis autolysin.

The mature forms of the extracellular muramidase-2 of Enterococcus hirae and Streptococcus faecalis autolysin have very similar primary structures. Each consists of an active-site-containing N-terminal domain fused to a multiple-repeat C-terminal domain. Polypeptide segments occurring at equivalent places in these two bacterial wall lytic enzymes have homologues in two phage lysozymes and in three functionally unrelated proteins, illustrating the principle that protein molecules frequently are constructed from modules that are linked in a single polypeptide chain.

Cloning and sequence analysis of the muramidase-2 gene from Enterococcus hirae.

Extracellular muramidase-2 of Enterococcus hirae ATCC 9790 was purified to homogeneity by substrate binding, guanidine-HCl extraction, and reversed-phase chromatography. A monoclonal antibody, 2F8, which specifically recognizes muramidase-2, was used to screen a genomic library of E. hirae ATCC 9790 DNA in bacteriophage lambda gt11. A positive phage clone containing a 4.5-kb DNA insert was isolated and analyzed. The EcoRI-digested 4.5-kb fragment was cut into 2.3-, 1.0-, and 1.5-kb pieces by using restriction enzymes KpnI, Sau3AI, and PstI, and each fragment was subcloned into plasmid pJDC9 or pUC19. The nucleotide sequence of each subclone was determined. The sequence data indicated an open reading frame encoding a polypeptide of 666 amino acid residues, with a calculated molecular mass of 70,678 Da. The first 24 N-terminal amino acids of purified extracellular muramidase-2 were in very good agreement with the deduced amino acid sequence after a 49-amino-acid putative signal sequence. Analysis of the deduced amino acid sequence showed the presence at the C-terminal region of the protein of six highly homologous repeat units separated by nonhomologous intervening sequences that are highly enriched in serine and threonine. The overall sequence showed a high degree of homology with a recently cloned Streptococcus faecalis autolysin.

Reduction mammaplasty: cosmetic or reconstructive procedure?

Ninety-two of 220 plastic surgeons submitted information from 600 women (the last 15 to 20 reduction mammaplasties by each surgeon) regarding height, weight, and amount of breast tissue removed. In a second survey to estimate percentages of women who sought reduction mammaplasties for purely cosmetic reasons, for mixed reasons, and for purely medical reasons, 132 of the same 220 surgeons responded. All women whose removed breast weight was less than the 5th percentile sought the procedure for purely cosmetic reasons, and all women whose breast weight was greater than the 22nd percentile sought the procedure for medical reasons. Those women whose removed breast tissue weight was between the 5th and the 22nd percentiles had mixed reasons for requesting the procedure.

Regulation of pyrimidine biosynthesis in Pseudomonas cepacia.

Pyrimidine biosynthesis was investigated in Pseudomonas cepacia ATCC 17759. The presence of the de novo pyrimidine biosynthetic pathway enzyme activities was confirmed in this strain. Following transposon mutagenesis of the wild-type cells, a mutant strain deficient for orotidine 5'-monophosphate decarboxylase activity (pyrF) was isolated. Uracil, cytosine or uridine supported the growth of this mutant. Uracil addition to minimal medium cultures of the wild-type strain diminished the levels of the de novo pyrimidine biosynthetic enzyme activities, while pyrimidine limitation of the mutant cells increased those de novo enzyme activities measured. It was concluded that regulation of pyrimidine biosynthesis at the level of enzyme synthesis in P. cepacia was present. Aspartate transcarbamoylase activity was found to be regulated in the wild-type cells. Its activity was shown to be controlled in vitro by inorganic pyrophosphate, adenosine 5'-triphosphate and uridine 5'-phosphate.

Lumbar spondylolisthesis: retrospective comparison and three-year follow-up of two conservative treatment programs.

Forty-eight patients with symptomatic back pain secondary to spondylolisthesis who were treated conservatively were followed for three years after initial examination to compare the outcomes of two exercise programs. The patients were divided into two groups--those doing flexion and those doing extension back strengthening exercises. All patients received instructions on posture, lifting techniques, and the use of heat for relief of symptoms. After three months, only 27% of patients who were instructed in flexion exercises had moderate or severe pain and only 32% were unable to work or had limited their work. Of the patients who were instructed in extension exercises, 67% had moderate or severe pain and 61% were unable to work or had limited their work. At three-year follow-up, only 19% of the flexion group had moderate or severe pain and 24% were unable to work or had limited their work. The respective figures for the extension group were 67% and 61%. The overall recovery rate after three months was 58% for the flexion group and 6% for the extension group. At three years these figures improved to 62% for the flexion group and dropped to 0% for the extension group. The literature is scarce regarding the applicability of conservative treatment programs for lumbar spondylolisthesis. On the basis of our findings, we suggest that if a conservative treatment program is elected, back flexion or isometric back strengthening exercises should be considered. The three-year follow-up data presented here lend support to this point of view.

Trends in incidence and clinical presentation of temporal arteritis in Olmsted County, Minnesota, 1950-1985.

Ninety-four Olmsted County, Minnesota residents with temporal arteritis (TA) initially diagnosed between 1950 and 1985 (incidence cohort) were identified. The age- and sex-adjusted incidence of TA per 100,000 population age 50 years or older was 17.0 (95% confidence interval [CI] 13.6-20.5), with a marked increase in incidence with age and a threefold greater incidence in women (23.4, 95% CI 18.2-28.7) than in men (7.4, 95% CI 3.7-11.0). The previously described secular increase in TA incidence in Olmsted County women continued from 1970 through 1985, while TA incidence in men declined in this latter time period. Although the frequency of classic clinical manifestations of TA declined over time, the percentage of patients undergoing biopsy who have positive specimens remained relatively constant (women 41%, men 26%). The incidence rate of temporal artery biopsy also increased for women during this period, but declined for men, suggesting that the differing trends in TA incidence by sex may be partially attributable to a detection bias. Future research in TA etiology and epidemiology should focus on possible causal factors linked to the differential TA incidence by sex.

Idiopathic membranous nephropathy: the natural history of untreated patients.

We reviewed the diagnostic features and clinical course of 140 patients with idiopathic membranous nephropathy who had their index renal biopsies performed at the Mayo Clinic between 1972 and 1984. There were 93 males and 47 females (average age, 50.8 +/- 17 years); 116 patients (83%) had the nephrotic syndrome and 42 (30%) were hypertensive at diagnosis. Eighty-nine patients were not treated with corticosteroid or immunosuppressive drugs and 51 patients were treated mainly with short-term courses of prednisone alone; a minority of patients also received meclofenamate, cyclophosphamide, azathioprine, or chlorambucil. Five-year survival, including patients who received dialysis or a renal transplant, was 85%, 75% at 10 years, and no different from expected survival; there was no difference between untreated and treated groups. Also, there were no differences in the outcomes of renal function and protein excretion between untreated and treated patients. Among 28 patients (20%) who developed end-stage renal disease, 17 showed rapid progression within 2.5 years after diagnosis. Fifteen of the 17 patients were males; all were severely nephrotic and had impaired renal function at diagnosis. Only 1 of 24 patients with nonnephrotic proteinuria at index renal biopsy progressed to end-stage renal disease. Overall, a level of baseline proteinuria of 10 g or more per 24 hours and variable blood pressure control in hypertensive patients were associated with renal progression.

The influence of diagnostic access bias on the epidemiology of sarcoidosis: a population-based study in Rochester, Minnesota, 1935-1984.

A population-based study was conducted among residents of Rochester, Minnesota from 1935-1984 to examine the influence of diagnostic access bias on the incidence and mode of presentation of clinically recognized sarcoidosis. Immigrants had an elevated risk of sarcoidosis and were more likely to present with asymptomatic sarcoidosis diagnosed on routine screening chest radiographs. Similar patterns were observed for health professionals, a group with markedly greater access to the diagnostic procedures which label them as having sarcoidosis. Sarcoidosis exhibits a spectrum of manifestations, ranging from a totally asymptomatic process discernible only by specific diagnostic scrutiny to a clinically obvious presentation with significant morbidity. For disease entities such as this, apparent patterns of occurrence may depend on differential access in the study population to the maneuvers necessary for diagnosis. Diagnostic access bias, in addition to other diagnostic biases, deserves more careful scrutiny in epidemiologic research.

Risk of cancer after herpes zoster: a population-based study.

Herpes zoster has been associated with immune suppression, as has an increased risk of cancer. To determine whether patients with herpes zoster are at increased risk for subsequent cancer, we followed 590 residents of Rochester, Minnesota, for 9389 person-years after the diagnosis of herpes zoster. Subsequent relative cancer risks, overall and by specific site, were determined for the entire cohort and selected subgroups. In addition, relative risks of cancer during various intervals after the diagnosis of herpes zoster were determined. The overall relative risk was 1.1 (95 per cent confidence interval, 0.9 to 1.3). Relative risks of specific cancer sites were not different from unity except for those for colon and bladder tumors in women, both of which were slightly elevated. Patients with disseminated, recurrent, or gangrenous zoster, with postherpetic neuralgia, and with ophthalmic zoster wee not at elevated risk for subsequent cancer. These findings do not support the investigation of patients for occult cancer at the time of diagnosis of herpes zoster or enhanced surveillance for cancer after such a diagnosis.

Subsequent cancer risk in the incidence cohort of Rochester, Minnesota, residents with diabetes mellitus.

Subsequent cancer incidence was determined in the population-based incidence cohort of Rochester, Minnesota, residents diagnosed with diabetes mellitus between 1945 and 1969. The relative risk of having cancer, excluding cervical and non-melanoma skin cancers, was not significantly increased following the diagnosis of diabetes mellitus. The potential biases of increased medical surveillance among diabetics and exacerbation of subclinical diabetes by occult malignancy did not appear to be important except in the case of subsequent pancreatic cancer.