Variations in microbial indicator densities in beach waters and health-related assessment of bathing water quality

Daily and hourly variations in microbial indicators densities in the beach-waters of Hong Kong have been described. The levels of Escherichia coli at a number of beaches was observed to be influenced by tide, and for staphylococci, by bather numbers. The tidal influence was most obvious during spring tides; and for the effect of bathers, during neap tides. Both organisms are present in high densities in external sources of faecal pollution of bathing beaches, with the average staphylococci to E. coli ratios being 0.04-3. Staphylococci may serve as an indicator of bather density and the risk of cross-infection amongst bathers (rather than as another indicator of faecal contamination) when the average staphylococci to E. coli ratio for a bathing beach is considerably higher than 3. The variability of microbial indicator densities means the routine sampling of bathing beaches should be carried out on weekend days with maximum numbers of swimmers exposed to the water, and spread throughout the bathing season.

Molecular and functional analysis of the virus- and interferon-inducible human MxA promoter

The virus- and interferon-inducible human MxA (IFI-78k) gene is a homologue of the murine influenza resistance gene Mx1. Three overlapping human cosmid clones covering most of the gene including its promoter region were isolated. Sequencing the 5' MxA cDNA derived by RT-PCR (reverse transcriptase-polymerase chain reaction) confirmed the most 5' putative transcriptional start site. The MxA promoter does not contain a TATA or CCAAT box but has three Interferon Stimulated Response Element (ISRE) motifs. Strong induction with type I interferons was demonstrated with a fragment containing only two ISREs in human L132 cells. This induced expression was not adversely affected by 2-aminopurine. However, the promoter showed constitutive expression in transiently or stably transfected murine LM cells.

Assessment of threshold and saturation pressure in the baroreflex function curve: a new mathematical analysis

The baroreflex function has been assessed with logistic function analysis, a mathematical model suitable for function curves of sigmoid shape. The nonlinear (sigmoid) relationship between carotid sinus pressure (CSP) and systemic arterial pressure (SAP) reflects threshold and saturation of the SAP responses to CSP changes. The threshold and saturation pressures (TP and SP) are often determined by gross inspection from the experimental recordings. Objective and accurate determination of TP and SP may be achieved by mathematical analysis. Kent et al. (Cardiology, Vol. 57, pp. 295-310, 1972) provided equations that estimated SP and TP to be +/- 1.317/k from the midrange CSP (k, the slope coefficient of a curve). Tan et al. (Circ. Res., Vol. 65, pp. 63-70, 1989) recently used an equation to calculate TP based on the consideration that it is about 95% of the maximal SAP. In this report, we elaborated new equations for the estimation of SP and TP, which approximate midrange pressure +/- 2/k. The accuracy of these new equations compared to other equations was tested using various sets of simulation data. In addition, experiments were conducted in anesthetized dogs with isolated carotid sinus. The open-loop CSP-SAP curves were obtained following various holding pressure (HPs) to demonstrate the phenomenon of baroreflex acute resetting. The effects of using different equations on the values of TP, SP, and delta TP/delta HP (extent of resetting) were analyzed. Both simulation and experimental data revealed that the equations of Kent et al. gave rise to values of TP and SP far different from the realistic values. The values of TP calculated by equation of Tan et al. were dependent on the maximal SAP and the slope of the function curve. The TP and SP (+/- 2/k from the midrange pressure of the sigmoid curve) obtained by our new equations were not significantly affected by the maximal SAP and the curve slope. The mathematical analysis may be particularly useful for comparison among various baroreflex curves with different maximal SAP and/or curve slope.

Vascular factors in isovolumic systemic and pulmonary circuit

Experiments were conducted in 12 pentobarbital-anesthetized dogs with sinus denervation and vagotomy. The chest was opened, and the heart was replaced by a roller pump with two perfusion lines. The systemic and pulmonary circulations (SC and PC) were perfused with a constant and adjustable flow (Q). Venous outflows were directly driven by pumps without passing through a reservoir. In each closed circuit, the total blood volume remained constant because inflow and outflow were simultaneously and equally altered. In both SC and PC, arterial pressure (Pa), i.e., systemic arterial and pulmonary arterial pressures (SAP and PAP), was a positive function of Q, and venous pressure (Pv), i.e., right atrial and left atrial pressures (RAP and LAP), was a negative function of Q. The first series of experiments involved three equal step reductions in Q from baseline to zero flow. The venous-to-arterial compliance ratio (Cv/Ca) was calculated from delta Pa/delta Pv and vascular resistance (VR) from (Pa - Pv)/Q. The values of Cv/Ca in SC increased from 9.3 +/- 0.4 to 14.5 +/- 1.1 and 21.9 +/- 1.4 (P less than 0.001) in the three-step Q reduction. VR in the SC was not significantly dependent on Q. In the PC, the Cv/Ca was approximately 2.0 and VR was 0.16 mmHg.ml-1.min.kg, both values being independent of Q. Multiple-step reduction in Q for regression equations was carried out in 8 of the 12 dogs. We found that only the SAP was a linear function of Q (ml.min-1.kg-1): SAP = 18.458 + 0.953Q.(ABSTRACT TRUNCATED AT 250 WORDS)

The influenza resistance murine Mx1 gene is constitutively expressed in the epithelia of the gastrointestinal, respiratory and uterine tracts

The murine Mx1 gene confers specific resistance against influenza in the inbred A2G mice and in vitro have been shown to be inducible with type I but not type II interferons. Contrary to expectation, we found by in situ hybridisation widespread Mx1 expression along the epithelia of the gastrointestinal, uterine and respiratory tracts in uninduced A2G mice. Several lines of evidence, including further enhancement of Mx1 expression during organ culture and gnotobiotic mice analyses, indicated that this apparent constitutive epithelial Mx1 expression was a locally induced response to stimuli present in the respective lumina. This phenomenon may be a feature found in other interferon-inducible and interferon genes.

Studies in the in vivo expression of the influenza resistance gene Mx by in-situ hybridisation

The inbred laboratory mouse strain A2G carries a functional, interferon type 1 inducible gene, Mx which upon expression confers specific resistance to an otherwise lethal dose of influenza virus. We investigated in vivo Mx gene expression by performing Northern hybridisation and in-situ hybridisation on A2G (Mx+) and (CBA/J x C57)F1 (Mx-) mice that were induced either with human, natural interferon; human, recombinant interferon or double stranded poly(I):(C). All 3 inducers were able to stimulate Mx expression in all organs examined in the A2G strain. However, contrary to previous reports, Mx expression was confined to a small number of cell types; the main contributor was most probably mononuclear cells. Specialised cells such as hepatocyte, nephron, ovarian follicle and seminiferous tubules did not show detectable Mx level. There was also constitutive Mx expression in the epithelia of uterus and duodenum which suggested direct gene activation independent of blood-bourne interferon.

Effects of nifedipine on systemic hydraulic vascular load in patients with hypertension

STUDY OBJECTIVE

The aim of the study was (1) to determine the difference in aortic input impedance and derived parameters between hypertensives and normotensives; and (2) to assess the acute effects of nifedipine on the aortic impedance, compliance, and resistance in patients with hypertension.

DESIGN

A high fidelity multisensor catheter (Millar) was used to obtain the aortic pressure and flow signals for impedance analysis. The acute effects of nifedipine on the impedance parameters were evaluated at steady state before and after (10-30 min) a sublingual dose of 10 mg.

PATIENTS

The patients included seven normotensive (mean blood pressure, 97 mm Hg) and nine hypertensive (mean blood pressure, 135 mm Hg), age matched, ethnic Chinese. Patients with clinical evidence of heart failure and valvular or congenital heart diseases were excluded.

MEASUREMENTS AND MAIN RESULTS

Pulsatile aortic flow and pressure were measured by Millar catheter inserted into the ascending aorta. Cross sectional area of aorta was estimated by echocardiograms. Cardiac output was determined by Fick principle with an oximeter. These data were subjected to Fourier analysis for impedance spectra. In comparison with normotensives, hypertensives had increased peripheral vascular resistance R, at 2751(705) v 1651(363) dyne.s.cm-5; increased characteristic impedance Zc, at 193(64) v 122(27) dyne.s.cm-5; and increased first zero crossing frequency of impedance phase angle fo, at 4.8(0.9) v 3.4(0.7) Hz. Arterial compliances corresponding to peak systolic pressure Cs were lower, at 0.32(0.19) v 0.90(0.32) ml.mm Hg-1, as was mean pressure Cm, at 0.55(0.25) v 1.24(0.38) ml.mm Hg-1, and end diastolic pressure Cd, at 0.83(0.29) v 1.65(0.44) ml.mm Hg-1. Although the values of external ventricular hydraulic power were higher in hypertensive subjects, the difference was not statistically significant. Nifedipine administration in 7/9 hypertensives significantly reduced R, from 2806(721) to 2433(664) dyne.s.cm-5; mean aortic pressure Pm, from 138(22) to 112(12) mm Hg; total external ventricular power Wt, from 1452(306) to 1121(135) mW; and steady external power Ws, from 1251(310) to 939(119) mW; but did not reduce Zc, fo, Cs, Cm, Cd, and oscillatory external power Wo.

CONCLUSIONS

The results indicate that (1) the stiffness of proximal aorta and vascular tone of peripheral arterioles are higher in hypertensives than in normotensives; (2) in hypertensive subjects, sublingual administration of nifedipine reduces the arterial pressure and peripheral arteriolar tone, but not the stiffness of proximal aorta; (3) the decrease in total external ventricular power in hypertensives treated with nifedipine results from a reduction in the steady, but not the oscillatory, component of hydraulic external ventricular power.

Health effects of beach water pollution in Hong Kong

Prospective epidemiological studies of beach water pollution were conducted in Hong Kong in the summers of 1986 and 1987. For the main study in 1987, a total of 18741 usable responses were obtained from beachgoers on nine beaches at weekends. The study indicated the overall perceived symptom rates for gastrointestinal, ear, eye, skin, respiratory, fever and total illness were significantly higher for swimmers than non-swimmers; and the swimming-associated symptom rates for gastrointestinal, skin, respiratory and total illness were higher at 'barely acceptable' beaches than at 'relatively unpolluted' ones. Escherichia coli was found to be the best indicator of the health effects associated with swimming in the beaches of Hong Kong. It showed the highest correlation with combined swimming-associated gastroenteritis and skin symptom rates when compared with other microbial indicators. A linear relationship between E. coli and the combined symptom rates was established. Staphylococci were correlated with ear, respiratory and total illness, but could not be used for predicting swimming-associated health risks. They should be used to complement E. coli. The setting of health-related bathing-water quality standards based on such a study is discussed.

Neurinoma of the spinal accessory nerve: report of a case

We report a patient with neurinoma of the spinal accessory nerve, who complained of intermittent occipital headaches, nausea, vomiting, blurred vision and unsteady gait. Neurological examination revealed papilledema, bilateral horizontal nystagmus and right cerebellar signs. Computed tomography revealed mild hydrocephalus, a low-attenuated lesion with a faint capsule after enhancement and partial compression of the 4th ventricle in the right posterior fossa. Vertebral angiography revealed no definite tumor vessels or stains. Under the impression of a posterior fossa tumor, a suboccipital craniectomy with a C1 and C2 laminectomy was performed. A 4 x 4 x 2.5 cm3 dumbbell tumor arising from the left spinal accessory nerve at the C2 level was found 4 x 4 x 2.5 cm3. The tumor extended upward through the foramen magnum with upward displacement of both tonsils to the right jugular foramen with slight adhesion to the right IX, X and XI cranial nerves. The left spinal accessory nerve was severed from the pedicle at the C2 level, and the tumor was totally removed. Diagnosis was made during the operation. The pathological examination showed neurinoma with cystic degeneration. During the following year, atrophy of the left sternocleidomastoid and trapezius muscles were noticed. Up to the time of this writing, there had been no clinical recurrence.

Urinary gonadotropin fragment, a new tumor marker. III. Use in cervical and vulvar cancers

The efficacy of urinary gonadotropin fragment (UGF) and squamous cell carcinoma antigen (SCC) measurements was examined in the management of cervical and vulvar cancers. Of women with benign gynecologic disease (n = 89) 7%, of women with cervical or vulvar intraepithelial neoplasia (n = 25) 8%, and of those with cervical or vulvar malignancies (n = 60) 47% had elevated UGF levels (greater than 3 fmol/ml). SCC at a cutoff of 2.5 ng/ml had a similar sensitivity, 43%, for the same group of cervical and vulvar malignancies. The populations recognized by SCC and UGF, however, only partially overlapped, so that together UGF and SCC were elevated in 62% of women with malignancies. The sensitivity of both markers was stage dependent, so that UGF and SCC detected 26 and 22%, respectively, of early (stage I or II), and 67 and 40%, respectively, of advanced (stage II or IV) cancers. We monitored the progress of 21 women undergoing therapy for cancer with UGF and SCC measurements. Of the 21, 13 (62%) had true-positive UGF levels and 11 (52%) had true-positive SCC levels when cancer was initially detected. The levels of UGF accurately reflected changing clinical observations in 11 of 21 (52%); those of SCC, in 6 of 21 (29%); and levels of either, in 14 of 21 (67%) cases. Recurrences occurred in 7 of the 21 cases. Rising SCC levels predicted (at an earlier clinic visit) the recurrence in 4 of the 7, and rising UGF levels in 5 of the 7 (includes the 4 detected by SCC) patients. While these numbers for UGF and SCC sensitivity are not ideal, until other markers become available, they are seemingly the best achievable. It is suggested that both UGF and SCC be used to monitor therapy and to detect recurrences of cervical and vulvar cancers.

Inositol uptake in rat aorta

The purpose of this study was to investigate the mechanism of inositol uptake into rat thoracic aorta. 3H-inositol uptake into deendothelialized aorta was linear for at least 2 h and was composed of both a saturable, Na(+)-dependent, and a nonsaturable, Na(+)-independent component. The Na(+)-dependent component of inositol uptake had a Km of 50 microM and a Vmax of 289 pmol/mg prot/h. Exposure to LiCl, ouabain, or Ca2(+)-free Krebs-Ringer bicarbonate solution inhibited uptake. Metabolic poisoning with dinitrophenol, as well as incubation with phloretin, an inhibitor of carrier-mediated hexose transport, also inhibited uptake. Exposure to norepinephrine decreased inositol uptake, while phorbol myristate acetate was without effect. Isobutylmethylxanthine significantly increased inositol uptake, while the increased uptake due to dibutyryl cyclic AMP and forskolin were not statistically significant. Sodium nitroprusside, an activator of guanylate cyclase, and 8-bromo cyclic GMP, were without effect on uptake, as was methylene blue, an inhibitor of guanylate cyclase. Inositol uptake into the aorta was increased when the endothelium was allowed to remain intact, although this effect was likely due to uptake into both the endothelial and smooth muscle cells. These results suggest that the uptake of inositol into vascular smooth muscle is: (1) dependent upon an inward Na(+)-gradient; (2) carrier mediated, and (3) inhibited by alpha 1 adrenoceptor agonists.

[Fleur-de-lis flap]

An Abbe flap with lateral vermilion extension (Fleur-de-lis flap) was used in four cases of secondary deformity of lip and palate with tightness and thinness of upper lip following primary cleft lip and palate surgery. The Abbe island flap was converted into fleur-de-lis flap with extensive mucosal wings to improve the fullness of the upper lip. The results were considered to be superior to those obtained by using an Abbe flap only. The balance between the lips was also improved. The technique is recommended in patients of secondary deformity of cleft lip with severe shortage and thinness of the lip vermilion.

Functional voiding disorders in women

From July 1986 to Dec 1987, 78 women complaining of frequency, urgency, dysuria and suprapubic discomfort were evaluated at our clinic. Their ages ranged from 20 to 68 (mean age: 38.2). The patients who were noted to have evidence of pyuria, neurological or gynecological abnormalities were excluded from the study. Urodynamic examinations including uroflowmetry, cystometry (CMG), urethral pressure profiles (UPP) and electromyography (EMG) of the external urethral sphincter were performed. The results revealed low flow rates in 56 patients (71.8%), non-relaxation of the external sphincter during voiding in 55 patients (70.5%), unstable bladder in 6 patients (7.7%) and a high maximal urethral closure pressure (MUCP) (greater than 80 cmH2O) in 44 patients (56.4%). The average volume of the cystometric capacity (250 +/- 86 ml) was decreased. The association between the low flow rate, non-relaxation of the external sphincter and a high MUCP was statistically significant. Urethral hypersensitivity has been recognized as being the major cause of these symptoms.

[Lateral calcaneal artery flap]

The lateral calcaneal artery flap provides a simple and reliable option for reconstructing the posterior heel defect. In our 10 cases including 3 diabetic patients, there was no flap necrosis, but one had the problem of wound healing. In another case, the skin graft over the flap donor site failed to take. All patients have protective sensation on the flap area, and 7 ambulatory patients can engage in a normal daily activity. Numbness over the lateral foot does not cause any trouble. There are a lot of spoke injuries in our 6-million-motorcycle country. When the conservative treatments do not achieve a satisfactory result, the lateral calcaneal artery flap should be the best surgical intervention for the defect less than 5 cm in diameter with bone or tendon exposure.

1,4-Dinitroimidazole and Derivatives. Structure and Thermal Rearrangement

Nitration of 4-nitroimidazole in acetic anhydride/glacial acetic acid gives 1,4-dinitroimidazole. The crystal and molecular structure of this compound have been determined by direct methods. Crystals are orthorhombic; P212121, a 5.853(3), b 9.591(8), c 10.392(5) � , V 583.4(7) � 3 , Dm 1 .76 g cm-1, Dc, 1 .80 g cm-1 (Z = 4); λ 0.71069 � ; T 173 K. The structure was refined to R = 0.048 for 926 reflections [I > 2 σ(1)]. Both 2-methyl-4-nitro- and 5-methyl-4-nitro-imidazoles N-nitrate under the same conditions. When heated in solution at 100-140�C 1,4-dinitro- and 2-methyl-1,4-dinitro-imidazoles rearrange to give C-nitro isomers and some denitration products, but 5(4)-methyl-1,4(5)-dinitroimidazole failed to give identifiable products.

Left ventricular diastolic function in hypertrophic cardiomyopathy: assessment by radionuclide angiography

Diastolic left ventricular function was studied in 20 patients with obstructive hypertrophic cardiomyopathy, 10 with apical hypertrophic cardiomyopathy, and 20 control subjects. The left ventricular time-activity curve was filtered using Fourier expansion with 4 harmonics. The first and second derivatives of the filtered curve were used to define various parameters of the left ventricle. Isovolumic relaxation period and time to peak filling rate were prolonged in obstructive hypertrophic cardiomyopathy and apical hypertrophic cardiomyopathy (101.56 +/- 44.81 msec, 105.19 +/- 45.27 versus 72.19 +/- 29.36 (CS) P less than 0.05; 169.70 +/- 50.73 msec, 173.83 +/- 50.53 versus 138.02 +/- 29.54 (CS) P less than 0.05, respectively). Rapid filling period, diastasis, atrial contraction period, time to peak filling rate-isovolumic relaxation period, and filling fraction of diastasis were not significantly different in these groups. Fasting filling fraction was 11% lower in hypertrophic groups than in control subjects. The filling fraction of atrial contribution was 12% higher in hypertrophic groups. We conclude: Isovolumic relaxation period, rapid filling phase, and diastasis atrial contraction period can be clearly defined by this technique. Impaired relaxation is an important determinant of decreased left ventricular filling in patients with obstructive hypertrophic cardiomyopathy and apical hypertrophic cardiomyopathy. Prolonged time to peak filling rate is mainly due to increased isovolumic relaxation period in hypertrophic patients. Atrial contraction contributes to more stroke volume in patients with hypertrophic cardiomyopathy.

Age-related changes in deformability of human erythrocytes

The present study was designed to further the characterization of age-related changes in the deformability of human erythrocytes. The top (approximately young) and bottom (approximately old) 10% fractions of density-separated red cells from ten normal donors were subjected to graded levels of shear stress in a rheoscope. Measurements were made of steady-state elongation (cells tank treading in a state of dynamic equilibrium) and the time course of shape recovery following abrupt cessation of shear. In parallel with the rheologic experiments, several physical and chemical properties were assayed to determine correlates of mechanical properties. These included mean cell volume, mean corpuscular hemoglobin concentration, type A1 hemoglobin, glucosylation of membrane proteins, and membrane phospholipid and protein concentration. The microrheologic observations revealed that only about 90% of the old cells retained their capacity to tank tread. However, the tank-treading cells elongated less than their younger counterparts at corresponding levels of shear stress, thus demonstrating a reduced level of deformability. Further analysis of the data indicates that increases in membrane viscosity and elastic modulus along with a significant loss in excess surface area contribute to the limitation of the ability of the older cells to change shape.

Location of intravenously injected kanamycin sulfate in the middle ear mucosa

Twelve guinea pigs were treated with intravenous kanamycin sulfate (KM) and sacrificed 2, 5, 10, and 30 min later to investigate its location in the middle ear mucosa, especially in the Eustachian tube (ET). Immunological examinations evidenced KM in the epithelial and subepithelial layers of the ET on each occasion of observation. But, it was never recognized in the tubal gland. These observations might indicate that clinically used drugs easily get to the ET except for the tubal gland which might have some barrier mechanism against foreign bodies.

Diphenylmethane diisocyanate (MDI)-induced asthma: evaluation of the immunologic responses and application of an animal model of isocyanate sensitivity

A worker developed two episodes of severe asthma 90 min after cutting a polyurethane plate made of diphenylmethane diisocyanate (MDI) using a rapidly turning carbide blade. Intradermal skin testing with MDI-human serum albumin (MDI-HSA) and p-tolyl isocyanate-HSA (p-TMI-HSA) were positive at 0.002 mg/ml. Control subjects showed no reaction at 2 mg/ml. Bronchial provocations of the worker with MDI-HSA and p-TMI-HSA, made 1 year after the occupational asthmatic episode, were negative at 10 mg/ml. Bronchial reactivity to methacholine decreased toward normal during a 2-year follow-up. RAST using MDI-HSA or p-TMI-HSA were strongly positive when compared with binding by sera from atopic controls which contained the same amount of total IgE. RAST titres decreased during a 1-year follow-up. In the MDI-HSA RAST, inhibition studies indicated specificity of antibodies for MDI-HSA. In the p-TMI-HSA RAST, p-TMI-HSA was a very effective inhibitor whereas MDI-HSA was not. These results indicated the formation of at least two distinct groups of IgE antibodies: those reactive with MDI, and those reactive with p-TMI determinants. Guinea pigs immunized with MDI formed antibodies with specificities similar to those of the patient. We conclude that the worker had occupational asthma accompanied by the formation of specific IgE antibodies of the specificities. The causal relationship of the antibodies to the occupational asthma remains uncertain.

Effects of higenamine on isolated heart adrenoceptor of rabbit

In the present study, effects of higenamine on various mechanical parameters of rabbit left atria as influenced by propranolol were investigated and compared to those of epinephrine. The following results are obtained: Higenamine, in a dose-dependent manner, increased the rate of tension development and shortened both the time to peak tension and the total duration of contraction. These effects of higenamine were competitively blocked by propranolol. The pA2 values of higenamine and epinephrine against propranolol were 8.58 +/- 0.14, 7.50 +/- 0.82 respectively, and the slopes by Schild plots were 0.97 and 0.99 with higenamine and epinephrine, respectively. The results indicate that the positive inotropic action of higenamine is likely due to stimulation of cardiac adrenoceptors.

Behavior of radionuclides in sanitary landfills

his study was undertaken to evaluate the possibility of disposing low-level radioactive waste in sanitary landfills with leachate containment to prevent environmental releases. To meet this objective, two simulated landfills, each 200 l. in volume and containing 55 kg of municipal refuse, were operated in the laboratory with simulated rainfall additions for a 9-month period to observe the extent to which radio-cobalt, -cesium, -strontium and tritium were leached into the liquid phase. One of the units was operated with leachate recycle, the other as a single pass control. Liquid samples were analyzed weekly for 3H, 58Co, 85Sr and 134Cs tracers. Weekly analyses were also performed for approximately 30 parameters to define the degree of stabilization of the waste. Major parameters included BOD, COD, pH and concentrations of specific organics, metals and gases. Concentrations of stable cobalt, strontium and cesium were also measured periodically. Soluble radioactivity levels in both systems were reduced by factors of 50 for 58Co, 5 for 85Sr and 7 for 134Cs, taking radioactive decay and dilution into account. Some radionuclide removal from the liquid phase was associated with major chemical changes in the landfills that occurred within 80 days for the control system and within 130 days for the recycle unit. Observed acid, sulfide, and CO2 concentrations suggested mechanisms for removing some of the radionuclides from leachate. Detection of 3H in the off-gas indicated that less than 1% of tritiated waste became airborne. The waste in the leachate recycle unit was more completely stabilized than in the control unit.