Thermodynamically controlled multiphase separation of heterogeneous liquid crystal colloids

Phase separation is a universal physical transition process whereby a homogeneous mixture splits into two distinct compartments that are driven by the component activity, elasticity, or compositions. In the current work, we develop a series of heterogeneous colloidal suspensions that exhibit both liquid-liquid phase separation of semiflexible binary polymers and liquid crystal phase separation of rigid, rod-like nanocellulose particles. The phase behavior of the multicomponent mixture is controlled by the trade-off between thermodynamics and kinetics during the two transition processes, displaying cholesteric self-assembly of nanocellulose within or across the compartmented aqueous phases. Upon thermodynamic control, two-, three-, and four-phase coexistence behaviors with rich liquid crystal stackings are realized. Among which, each relevant multiphase separation kinetics shows fundamentally different paths governed by nucleation and growth of polymer droplets and nanocellulose tactoids. Furthermore, a coupled multiphase transition can be realized by tuning the composition and the equilibrium temperature, which results in thermotropic behavior of polymers within a lyotropic liquid crystal matrix. Finally, upon drying, the multicomponent mixture undergoes a hierarchical self-assembly of nanocellulose and polymers into stratified cholesteric films, exhibiting compartmentalized polymer distribution and anisotropic microporous structure.

Objective identification of dental abnormalities with multispectral fluorescence imaging

Sensitive methods that can enable early detection of dental diseases (caries and calculus) are desirable in clinical practice. Optical spectroscopic approaches have emerged as promising alternatives owing to their wealth of molecular information and lack of sample preparation requirements. In the present study, using multispectral fluorescence imaging, we have demonstrated that dental caries and calculus can be objectively identified on extracted tooth. Spectral differences among control, carious and calculus conditions were attributed to the porphyrin pigment content, which is a byproduct of bacterial metabolism. Spectral maps generated using different porphyrin bands offer important clues to the spread of bacterial infection. Statistically significant differences utilizing fluorescence intensity ratios were observed among three groups. In contrast to laser induced fluorescence, these methods can provide information about exact spread of the infection and may aid in long term dental monitoring. Successful adoption of this approach for routine clinical usage can assist dentists in implementing timely remedial measures.

Synergistic proinflammatory interactions of microbial toxins and structural components characteristic to moisture-damaged buildings

Indoor exposure to microbes and their structural and metabolic compounds is notoriously complex. To study proinflammatory interactions between the multiple microbial agents, macrophages derived from human THP-1 monocytic cells were exposed to several concentrations of microbial toxins alone (emodin, enniatin B, physcion, sterigmatocystin, valinomycin) and in combination with microbial structural components (bacterial lipopolysaccharide [LPS] or fungal β-glucan). While the expression of proinflammatory cytokines TNFα and IL-1β to single toxins alone was modest, low-dose co-exposure with structural components increased the responses of emodin, enniatin B, and valinomycin synergistically, both at the mRNA and protein level, as measured by RT-qPCR and ELISA, respectively. Co-exposure of toxins and β-glucan resulted in consistent synergistically increased expression of several inflammation-related genes, while some of the responses with LPS were also inhibitory. Co-exposure of toxins with either β-glucan or LPS induced also mitochondrial damage and autophagocytosis. The results demonstrate that microbial toxins together with bacterial and fungal structural components characteristic to moisture-damaged buildings can have drastic synergistic proinflammatory interactions at low exposure levels.

Blood pressure and renin during treatment with pindolol

Beta-receptor blocking drugs are known to decrease BP and plasma renin activity (PRA) in hypertensive patients. We treated 31 hypertensive patients with the beta-receptor blocking drug, pindolol, for 3 months. During the first month (mean daily dose 10 mg) and the second month (mean daily dose 14.2 mg) BP and PRA decreased. During the third month of pindolol therapy (mean daily dose 19.0 mg) 16 patients had an unexpected rise of BP towards control levels and PRA levels rose, too. The remaining 15 patients maintained a good antihypertensive drug effect and suppression of PRA. Pretreatment PRA was not related to BP reduction. The change in diastolic BP was not significantly related to that in PRA. The results indicate that low doses of pindolol,10-15 mg daily, will suffice in mild essential hypertension. An increasing frequency of partial drug resistance may be a result of unnecessarily high doses of pindolol.

Influence of physical activity and maturation status on bone mass and geometry in early pubertal girls

This study aimed to evaluate the influence of leisure-time physical activity on the development of bone mass and density in early pubertal girls. Scores of physical activity were obtained from 242 Finnish girls (10-12 years old within Tanner Stages I-II) using a questionnaire. Bone mass and density were assessed using different densitometric techniques. At Tanner Stage I, active girls had significantly higher bone mineral mass (BMC) and areal bone mineral density (aBMD) of the whole body and cortical volumetric BMD and thickness of the tibial shaft compared with sedentary girls (P<0.05). On the other hand, the active girls at Tanner Stage II showed significantly higher values only in BMC and aBMD at the lumbar spine (P=0.017 and P=0.007, respectively). These indicated that girls at Tanner Stage I with higher leisure-time physical activity level benefited more from physical activity in terms of their bone development than their less active counterparts. Our results provide evidence that the most beneficial time for physical exercise to exhibit its effect on bone development is in the earlier pubertal period for normal school children, but the positive effect on the lumbar spine is also demonstrated in Tanner Stage II.

Apparatus to test insertion and removal torque of bone screws

This paper describes affordable equipment for testing bone screw torque, corresponding to ASTM standard F543-00 for testing metallic medical bone screws. Correct testing of thin and long bone screws is essential due to screw failures during insertion and removal of the screws. Furthermore, insertion torque is an important factor in predicting fixation strength, screw pull-out force and effects of surface treatment of screws. The capability of the custom-built tester was determined using polytetrafluoroethylene and wood disc samples and bone screws. Bovine cortical bones allowed testing to the failure limit, i.e. the torque increased in long screws to the fracture limit. For 2.7 and 3.5 mm thick self-tapping cortical bone screws, the failure torques were 30-50 per cent higher than the minimum values required by the standard (1.0 and 2.3 N m respectively). The equipment provided reproducible results and fulfilled the ASTM standard very well. Preliminary testing with amorphous diamond coated bone screws showed good durability of the coating and on average 10-15 per cent lower torque values compared with uncoated screws. The equipment can be used to measure insertion and removal torques as described in the standard. Furthermore, it also allows testing of normal screws and bolts.

Loss of time-organized sympathetic skin responses in acute psychosis

The aim of this study was to differentiate the response pattern characteristics of sympathetic skin responses (SSR) between unmedicated first psychotic subjects and healthy controls. We recorded SSR to novel auditory stimuli in 13 psychotic subjects and in 19 controls. There was no constant delay between a sudden change in the acoustic surroundings and SSR in psychotic subjects, whereas regularly this delay was 1.3 to 1.8 seconds in controls. The validity of the test was evaluated by blind rating responses to two categories. The lack of a regular time delay between a novel auditory stimulus and SSR suggests a timing disturbance in the neural networks regulating the autonomic nervous system responses in acute psychosis. Our finding and method may have future implications in evaluation of subtle autonomic nervous system alterations related, e.g., to drug effects.

Antidromic corticospinal tract potential of the brain

OBJECTIVE

To describe a novel potential component (antidromic corticospinal tract potential, ACSP) of the brain after translaminar spinal stimulation of a relaxed patient during scoliosis surgery. To study the origin of this component and to compare its source to known sources of the somatosensory evoked potentials (SEPs).

METHODS

We studied 17 consecutive patients during posterior scoliosis surgery. SEPs and ACSPs were elicited by translaminar spinal stimulation at the Th 2 and L 1 levels. ACSPs and SEPs were recorded on the scalp midline. Neurogenic motor evoked potentials (NMEPs) were recorded on the popliteal spaces. Preoperative tibial SEPs were also recorded.

RESULTS

ACSP was distinctly separated from the corresponding spinally evoked cortical SEP that showed longer latency than the ACSP. ACSPs decreased and disappeared when stimulation was moved to the caudal direction in the conus region while SEP persisted. In addition, the hemispheric origin of ACSP was confirmed with multichannel midline recordings of the scalp and neck. Thus there was no confusion to the response of nucleus gracilis, corresponding the P 31 response of the tibial nerve SEP.

CONCLUSIONS

The origin of ACSP seemed to be in the rostral part of the corticospinal tract. ACSP diminished in the conus region when stimulation was moved caudally and it disappeared when the stimulus was given to the root level. This proves that ACSP is not a response of the somatosensory tract, instead ACSP represents antidromic response of the pyramidal tract. ACSP can be used in monitoring of the motor tracts during scoliosis surgery together with NMEPs.

P300 sequence effects differ between children and adults for auditory stimuli

Variation of the P300 component was studied in normal children and adults during an auditory oddball paradigm. In children, the target stimuli that were preceded by a large number of standard stimuli elicited about twice as large P300 with a significantly shorter latency, a more widespread distribution, and an earlier positivity in the frontal area than those that were preceded by a small number of standard stimuli. The P300 variation was not as marked in adults as in children. Based on the context updating theory of the P300, the finding suggests that a long intertarget interval (ITI) results in a profound decay of the neural representation of the target stimulus in children; consequently, more resources are needed to update the neural representation, and the target may even be processed as a novel input. The P300 variation may provide information about the brain functions related to memory, attention, and orienting in children. This variation should be considered when assessing cognitive brain functions with event-related potentials in children.

Low diastolic blood pressure and mortality in a population-based cohort of 16913 hypertensive patients in North Karelia, Finland

OBJECTIVE

To examine the relationship between mortality and diastolic blood pressure during treatment.

DESIGN

A prospective follow-up of a population-based dynamic cohort of hypertensive patients.

SETTING

Province of North Karelia, eastern Finland.

PATIENTS

A cohort of 16 913 North Karelian hypertensive patients in hypertension register of the North Karelia Project, who had been followed up since 1972 until the end of 1985. Most of these patients had been under antihypertensive drug therapy during the follow-up.

MAIN OUTCOME MEASURES

Death: all deaths (n = 4490), deaths from cardiovascular disease (n = 2995) and deaths from non-cardiovascular disease (n = 1495).

RESULTS

Of all deaths, 17% of those among men and 24% of those among women were of patients with mean diastolic blood pressures less than 90 mmHg. We found a U-shaped relationship between diastolic blood pressure and total, cardiovascular and non-cardiovascular mortalities. We investigated this relationship in more detail using Cox regression model. Low diastolic blood pressure was associated independently with increased mortality for the patients aged 50 years or more at baseline. The occurrence of cardiac failure and other cardiovascular complications of hypertension were more important determinants of mortality than was low diastolic blood pressure alone.

CONCLUSIONS

We demonstrated that there is an association between low diastolic blood pressure and mortality for treated hypertensive patients aged 50-69 years. The clinical importance of this relationship for patients without any cardiovascular complications of hypertension seems negligible. For patients with complications, these complications are likely to be primary factors causing greater than normal mortality and low diastolic blood pressure is mostly a secondary phenomenon. Our data do not lend support to speculations that there is overtreatment of hypertension, which would increase mortality through making diastolic blood pressures too low.

Long term treatment of severe hypercholesterolaemia with guar gum

The long term efficacy of granulated guar gum, 15-30 g per day, was studied in 23 patients with severe hypercholesterolaemia (serum cholesterol concentration between 8.0 and 14.3 mmol/l). Originally, 29 patients participated in the study. Two patients dropped out because of gastrointestinal side effects, two others were not willing to complete the study without any given reason, and two discontinued the study because of hospitalization. A 1-month placebo period preceded the guar gum treatment, and another 1-month placebo period followed after 50 weeks of active treatment. The serum total cholesterol concentration (mean +/- SEM) was reduced from 10.0 +/- 0.4 mmol/l to 8.2 +/- 0.3 mmol/l (P less than 0.001) after 8 weeks and to 9.0 +/- 0.4 mmol/l (P less than 0.001) after 50 weeks on guar gum. During the second placebo period serum cholesterol returned to the pretreatment level. After 34 weeks of active treatment the serum LDL-cholesterol concentration had fallen by 15% and that of apoprotein B by 14% from the baseline. The changes in lipid and lipoprotein levels were independent of the initial values and the type of hypercholesterolaemia. Serum triglycerides, HDL-cholesterol, body weight and blood pressure showed no significant changes during the trial. Of the study subjects, 20 reached the maximum intended dose of 30 g per day guar gum between 8 and 14 weeks and thereafter 11 subjects continued the dose of 30 g/day while 12 subjects reduced the dose to 15-25 g/day.(ABSTRACT TRUNCATED AT 250 WORDS)

Sustained release verapamil in hypertension. Results from a noninvasive ambulatory blood pressure monitoring and a clinical study

The antihypertensive effect of a new sustained-release matrix formulation of verapamil 200 mg was investigated in a dose-response study in patients with mild to moderate essential hypertension. Noninvasive ambulatory blood pressure measurements were recorded over 24 h in 6 patients with diastolic blood pressure greater than or equal to 100 mmHg. The patients received sustained-release verapamil 200 mg once daily and twice daily in a randomized order. Each medication period lasted 2 weeks. Verapamil 200 mg twice daily had a better antihypertensive effect than the same dose once daily. After a 6-week placebo period 27 patients with a diastolic blood pressure greater than or equal to 100 mmHg were included in a double-blind clinical trial. The patients received sustained release verapamil 200 mg once daily and twice daily in a randomized crossover manner. Each medication period lasted 6 weeks, with an intervening 6-week placebo period. A diastolic blood pressure of less than or equal to 95 mmHg was achieved in 6 patients with the once-daily regimen and in 14 with the twice-daily regimen. The mean fall in diastolic blood pressure was 4 and 9 mmHg, respectively (p less than 0.05). We conclude that sustained-release verapamil 200 mg once daily gives a satisfactory blood pressure response only in a minority of patients, while 200 mg twice daily has a significantly better antihypertensive effect. Both doses were well tolerated.

The Edinburgh-Helsinki study: a comparison of dental care for children

A comparison was undertaken of dental care for children in Edinburgh and Helsinki. The evaluation centred upon an epidemiological investigation of the dental health of children in the 5-, 12- and 15-year age groups. This was performed by examiners using standardized procedures who were drawn from both countries. They employed an established system of data recording and processing (SPEED). Using these data, and background information from official and other sources, an assessment was made of the effectiveness, adequacy, efficiency and appropriateness of the services. Children's dental health, particularly in the youngest age group, was generally better in Helsinki than in Edinburgh as were both the population coverage and extent to which disease was controlled. However, the services in Edinburgh were marginally the more economically efficient. This arose from their being provided mainly by independent contractors working under a fee per item of service rather than by a public salaried system. In neither city was the delivery of dental services supplemented by water fluoridation nor was extensive use made of auxiliary personnel. The decrease in caries prevalence in recent years has profound implications for the dental services in both countries. It calls for continuing re-appraisal of present policies on expenditure, manpower, dental education and ways of delivering dental care.

Antihypertensive therapy in patients above age 60 with systolic hypertension. A progress report of the European Working Party on High Blood Pressure in the Elderly (EWPHE)

1. Although systolic blood pressure elevation is responsible for increased incidence of cardiovascular accidents in old people, the preventive benefit of lowering systolic hypertension in elderly has not been confirmed. 2. A double blind study comparing the effects of a placebo and of an active regimen (hydrochlorothiazide-triamterene with or without methyldopa) in people over 60 years with isolated systolic hypertension has been undertaken by the European Working Party on High blood pressure in the Elderly (EWPHE). 3. The actively treated group shows a lowered sitting blood pressure (-15/6 mm Hg), a mild increase of serum creatine, serum uric acid and blood glucose and a mild decrease of serum potassium after two years of treatment when compared to the spontaneous changes observed in the placebo treated group. 4. The study is continuing to evaluate if the blood pressure reduction prevents or reduces the incidence of cardiovascular accidents, although some biochemical changes were provoked by the treatment.

Antihypertensive therapy in patients above age 60 years (Fourth Interim report of the European Working Party on High Blood pressure in Elderly: EWPHE)

1. A total of 450 hypertensive patients above the age of 60 years have entered the double-blind multicentre trial of the European Working Party on High blood pressure in Elderly (EWPHE). After stratification and randomization half were treated with one capsule daily containing 25 mg of hydrochlorothiazide and 50 mg of triamterene and half were given placebo. In those receiving active treatment, if blood pressure control was not adequate they were given a second capsule and if necessary up to 2 g of methyldopa/day.

2. No significant differences between the groups were present before randomization. A significant blood pressure difference of 25/10 mmHg was obtained between the groups and maintained during 4 years of follow-up. No major disturbances in serum potassium or serum sodium were noted with the present drug combination.

3. During the initial phase an increase in serum creatinine and serum uric acid was noted in the actively treated group, which was maintained during the later years. This increase in serum creatinine in the actively treated group was related (P = 0·003 and r = −0·247) to the decrease in sitting systolic blood pressure. Changes in serum uric acid were (r = 0·3 and P = 0·003) correlated with the changes in serum creatinine both in the placebo and in the actively treated group, but independent of the change in creatinine; the serum uric acid was on average 1 mg higher in the actively treated than in the placebo group.

4. Fasting blood glucose did not change significantly in the placebo-treated group but in the active treatment group the rise was statistically significant.

5. A favourable influence on prognosis by active treatment can be expected on the basis of the blood pressure reduction and in the absence of major electrolytes disturbances. However, the balance between this decreased risk and the increased risk produced by the rise in blood glucose and the other treatment effects remains to be determined. Therefore the trial continues and more patients are being admitted.