P1833The c-fos mRNA expression reveals persistent myocardial stretch in the right ventricle during asphyxiated cardiac arrest

Background

Donation after circulatory death (DCD) heart transplantation has been debated over the past decades because of the shortage of donor. The right ventricular dysfunction is one of the remaining problems for clinical implication of DCD heart transplantation. DCD hearts suffering from the volume overload have a potential to aggravate the right ventricular dysfunction after heart transplantation. The c-fos mRNA is one of the “immediate” response genes to mechanical stresses, such as myocardial cell stretch, without neural and humoral factors. In this study, we assessed myocardial stretch during asphyxiated cardiac arrest using c-fos mRNA expression.

Purpose

The purpose of this study is to reveal the impact of right ventricular volume overload during asphyxiated cardiac arrest.

Methods

Male Wistar rats (8 weeks of age, n=18) were anesthetized with paralyzed ventilation. The trachea was dissected and ligated to initiate asphyxiation. Hearts were harvested at 3 time points: 0, 15 and 30 minutes after termination of the ventilation. Free walls of right and left ventricle were sectioned and immersed in RNA stabilization solution as soon as possible. Total RNA was extracted from these tissues using a guanidine thiocyanate-phenol-chloroform method and cDNA was synthesized using a reverse transcriptase. Next, we measured the quantified expression level by using the droplet digital PCR method with a probe and primers for c-fos gene. Expression of c-fos level was divided by extracted TATA binding protein (TBP) level as a control marker, the ratio of c-fos and TBP was used in analysis.

Results

In the left ventricle, the expression of c-fos rapidly increased by 15 minutes (0.81±0.24 (c-fos/TBP), p<0.05 by one-way ANOVA followed by the Dunnett's test) compared to at 0 minutes (0.21±0.06), but the expression level recovered to the baseline level at 30 minutes after termination of the ventilation (0.19±0.03). On the other hand, in the right ventricle, the c-fos expression was gradually elevated and peaked at 30 minutes (0.88±0.20, p<0.05 by the Dunnett's test) compared to at 0 minutes (0.22±0.05).

Conclusion

These results suggest that the volume overload to the right ventricle during asphyxiated cardiac arrest prolongs compared to that to the left ventricle, which may cause the right ventricular dysfunction after DCD heart transplantation.

Cost-effectiveness of cognitive remediation and supported employment for people with mental illness: a randomized controlled trial

BACKGROUND

Little is known about the economic benefits of cognitive remediation and supported employment (CR + SE). The present study aimed to investigate the cost-effectiveness of CR + SE compared with traditional vocational services (TVS).

METHOD

Individuals with mental illness and low cognitive function were recruited at six sites in Japan. A total of 111 participants were randomly allocated to the CR + SE group or the TVS group. Clinical and vocational outcomes were assessed at baseline and 12-month follow-up. Service utilization data were collected monthly. The data on outcomes and costs were combined to examine cost-effectiveness.

RESULTS

The data were obtained from a total of 92 participants. The CR + SE group resulted in better vocational and clinical outcomes (employment rate, 62.2%; work tenures, 78.6 days; cognitive improvement, 0.5) than the TVS group (19.1%, 24.9 days and 0.2). There was no significant difference in mean total costs between the groups (CR + SE group: $9823, s.d. = $6372, TVS group: $11 063, s.d. = $11 263) with and without adjustment for covariates. However, mean cost for medical services in the CR + SE group was significantly lower than that in the TVS group after adjusting covariates (Β = -$3979, 95% confidence interval -$7816 to -$143, p = 0.042). Cost-effectiveness acceptability curves for vocational outcomes illustrated the high probabilities (approximately 70%) of the CR + SE group being more cost-effective than TVS when society is not willing to pay additional costs.

CONCLUSIONS

CR + SE appears to be a cost-effective option for people with mental illness who have low cognitive functioning when compared with TVS.

NaCl responsive taste cells in the mouse fungiform taste buds

Previous studies have demonstrated that rodents' chorda tympani (CT) nerve fibers responding to NaCl can be classified according to their sensitivities to the epithelial sodium channel (ENaC) blocker amiloride into two groups: amiloride-sensitive (AS) and -insensitive (AI). The AS fibers were shown to respond specifically to NaCl, whereas AI fibers broadly respond to various electrolytes, including NaCl. These data suggest that salt taste transduction in taste cells may be composed of at least two different systems; AS and AI ones. To further address this issue, we investigated the responses to NaCl, KCl and HCl and the amiloride sensitivity of mouse fungiform papilla taste bud cells which are innervated by the CT nerve. Comparable with the CT data, the results indicated that 56 NaCl-responsive cells tested were classified into two groups; 25 cells ( approximately 44%) narrowly responded to NaCl and their NaCl response were inhibited by amiloride (AS cells), whereas the remaining 31 cells ( approximately 56%) responded not only to NaCl, but to KCl and/or HCl and showed no amiloride inhibition of NaCl responses (AI cells). Amiloride applied to the basolateral side of taste cells had no effect on NaCl responses in the AS and AI cells. Single cell reverse transcription-polymerase chain reaction (RT-PCR) experiments indicated that ENaC subunit mRNA was expressed in a subset of AS cells. These findings suggest that the mouse fungiform taste bud is composed of AS and AI cells that can transmit taste information differently to their corresponding types of CT fibers, and apical ENaCs may be involved in the NaCl responses of AS cells.

Angiotensin AT(1) receptor antagonism normalizes retinal blood flow and acetylcholine-induced vasodilatation in normotensive diabetic rats

AIMS/HYPOTHESIS

The renin angiotensin system is emerging as a potential therapeutic target for diabetic retinopathy. This study examines the effects of angiotensin-converting-enzyme inhibition by captopril and angiotensin AT(1) receptor antagonism using candesartan-cilexetil on retinal blood flow and acetylcholine-stimulated vasodilatation in normotensive diabetic rats.

METHODS

Non-diabetic or streptozotocin-induced diabetic rats were treated for 2 weeks with captopril (100 mg/kg/day) or candesartan cilexetil (2 mg/kg/day). Retinal haemodynamics were measured using video fluorescein angiography. Effects of exogenous acetylcholine on retinal haemodynamics were examined following intravitreal injection. Total retinal diacylglycerol was labelled using diacylglycerol kinase, separated by thin-layer chromatography, and quantified using autoradiography.

RESULTS

Diabetic rats had prolonged retinal mean circulation time and decreased retinal blood flow compared with non-diabetic rats. Treatment of diabetic rats with either captopril or candesartan blocked the development of these blood flow abnormalities. Intravitreal injection of acetylcholine (10(-5) mol/l) in non-diabetic rats increased retinal blood flow by 53.9+/-22.0% relative to baseline whereas this response to acetylcholine was blunted in diabetic rats (4.4+/-19.6%, p<0.001). Candesartan treatment of diabetic rats restored the acetylcholine-stimulated retinal blood flow response to 60.0+/-18.7% compared with a 56.2+20.1% response in candesartan-treated non-diabetic rats. Total retinal diacylglycerol levels were increased in diabetic rats (3.75+/-0.98 nmol/mg, p<0.05) compared with non-diabetic rats (2.13+/-0.25 nmol/mg) and candesartan-treatment of diabetic rats normalized diacylglycerol levels (2.10+/-0.25 nmol/mg, p<0.05).

CONCLUSION/INTERPRETATION

This report provides evidence that angiotensin-converting enzyme inhibition and AT(1) receptor antagonism ameliorates retinal haemodynamic dysfunctions in normotensive diabetic rats.

Progressive change of optical coherence tomography scans in retinal degeneration slow mice

OBJECTIVE

To study whether optical coherence tomography (OCT) scans correlate retinal histologic findings with the progression of retinal degeneration in retinal degeneration slow (rds) mice.

METHODS

Sensory retinal thickness (SRT) and outer retinal thickness (ORT), representing photoreceptor cell layer, in temporal retina at a distance 1 to 2 disc diameters from the optic disc were measured using scan profile in OCT from 6 healthy mice (16 weeks old) and 2-week-old (n = 6), 6-week-old (n = 4), and 60-week-old (n = 2) rds mice. Histologic sections were obtained from Epon-embedded retinas from the corresponding location.

RESULTS

Cross-sectional OCT images correlated to the corresponding histologic sections in each mouse. Both SRT and ORT of 2-week-old rds mice (150 +/- 4 microm and 28 +/- 4 microm, respectively) lacking photoreceptor outer segments were already shorter than those of healthy mice (174 +/- 5 microm and 37 +/- 6 microm, respectively) (P<.001). In 6-week-old mice, microscopic findings revealed a decreased number of nuclei in the outer nuclear layer, and SRT and ORT (136 +/- 2 microm and 20 +/- 1 microm, respectively) were shorter than those of 2-week-old rds mice (P<.001). The SRT of 60-week-old rds mice without a photoreceptor layer was remarkably reduced (120 +/- 7 microm), and no ORT could be measured.

CONCLUSION

Our findings suggest a possible relationship between SRT and ORT, as measured by OCT, and histologic change in retinal degenerative diseases.

CLINICAL RELEVANCE

The quantitative analysis obtained by OCT scans may have potential to detect progressive change in degenerative retina and may be used in studying human retinal degeneration.

Electroretinogram in the diagnosis of endophthalmitis after intraocular lens implantation

PURPOSE

To determine whether single flash electroretinograms can assist in the diagnosis of eyes with endophthalmitis after intraocular lens implantation.

METHODS

Sixteen eyes with postoperative endophthalmitis treated with vitrectomy or intraocular lens removal were studied. The preoperative electroretinogram findings, duration until the onset of endophthalmitis, culture results, and postoperative visual acuity were analyzed.

RESULTS

Four eyes with a b-wave/a-wave (b/a) ratio less than 1.0 and early onset of endophthalmitis within 1 week had worse postoperative visual acuity (no light perception to 20/200) than the other 12 eyes (20/100 to 20/15) (P =.0035). Pseudomonas aeruginosa and Enterococcus faecalis were cultured in these 4 eyes.

CONCLUSION

The combination of a b/a ratio less than 1.0 and early onset of endophthalmitis may indicate poor prognosis in a patient with postoperative endophthalmitis.

Vitreoretinal traction maculopathy caused by retinal diseases

PURPOSE

To study the morphological findings of vitreoretinal traction maculopathy caused by retinal vascular diseases and their changes after vitrectomy.

METHODS

Optical coherence tomographic images of 13 eyes of 12 cases were evaluated before and after vitrectomy.

RESULTS

The tractional force appeared to be mainly tangential with a possible anterior vector in 11 eyes, and mainly in the anterior direction in 2 eyes. After surgery, the increased foveal thickness decreased markedly in all eyes, and visual acuity improved in 8 eyes.

CONCLUSION

Preoperative optical coherence tomographic examination can reveal the fine structure of vitreoretinal separations and adherences caused by retinal vascular diseases. These observations permitted better surgical planning and results.

Vitrectomy for endophthalmitis after intraocular lens implantation

PURPOSE

To report the results of vitrectomy and intraocular lens (IOL) removal for the treatment of endophthalmitis after IOL implantation.

METHODS

We reviewed 14 eyes of 14 patients who underwent pars plana vitrectomy because of postoperative endophthalmitis. Culture results, surgical methods, and visual outcome are presented.

RESULTS

The cultures grew Enterococcus faecalis (n = 3), Staphylococcus epidermidis (n = 2), Propionibacterium acnes (n = 1), and gram-negative bacillus (n = 3). The eyes infected with E. faecalis had poor visual outcome. Eleven eyes treated by the combination of pars plana vitrectomy and IOL removal did not have a recurrence. The remaining 3 eyes on which only vitrectomy was performed had a recurrence, and the additional procedures consisting of vitrectomy and IOL removal could result in eradicating endophthalmitis.

CONCLUSIONS

A higher rate of E. faecalis was detected and these eyes had severe inflammation and poor visual outcome. Combined vitrectomy and IOL removal may be a more certain method to prevent recurrence.

Stenotrophomonas maltophilia endophthalmitis after intraocular lens implantation

BACKGROUND

Stenotrophomonas maltophilia is an opportunistic, gram-negative bacillus. Endophthalmitis induced by S. maltophilia has been described in only two cases after intraocular lens implantation. We report S. maltophilia endophthalmitis in two patients with diabetes mellitus after intraocular lens implantation and compare the characteristics of the S. maltophilia-induced endophthalmitis with two previous cases.

METHODS

A 68-year-old woman and a 74-year-old man with diabetes mellitus developed S. maltophilia endophthalmitis within 5 days of intraocular lens implantation. We performed intraocular lens removal and vitrectomy, which resolved the inflammation. No recurrences were found.

RESULTS

Cultures grew S. maltophilia in both cases, and one of the organisms was multi-resistant. The final visual acuity was counting fingers and 0.3. The first case revealed a tractional retinal detachment during vitrectomy.

CONCLUSIONS

S. maltophilia is a potential opportunistic intraocular pathogen, and the incidence of multiresistant S. maltophilia is increasing. S. maltophilia causes acute endophthalmitis, and its prognosis may not be poor unless the eye has a history of serious disease before the cataract surgery. The combined procedure of intraocular lens removal and vitrectomy was useful in resolving the inflammation and preventing recurrences.

Kinetics of foveal cone photopigment in myopia without chorioretinal degeneration

PURPOSE

To study the early changes in the outer retina of myopic eyes, we performed fundus reflection foveal cone densitometry in 45 subjects with normal visual acuity and no chorioretinal degeneration (ages: 18-47 years, refraction; +2.00-(-14.50) diopters).

METHODS

After full bleaching, the density of the photopigment was measured for 7 minutes by using a test spot, 562 nm in wavelength and 1 degrees in diameter, focused on the fovea. We calculated the density difference (DD) and the time constant (TC) of photopigment regeneration.

RESULTS

Although we found no correlation between the DD and the refractive error, there was a significant increase in TC as the refractive error increased (r = 0.50, P < 0.01).

CONCLUSIONS

These findings indicated that the kinetics of cone pigments become abnormal preceding the loss of cone cells or chorioretinal degeneration in high myopia.

[Foveal cone densitometry in high myopia]

We performed foveal cone densitometry using a modified fundus camera in 17 eyes of 17 normal subjects (age range, 20 to 47 yr, refractive error, +2.0 to -2.5 D) and 15 eyes of 15 high myopia subjects with normal visual acuity (age range, 18 to 46 yr, refractive error, -9.0 to -14.5 D). After fully bleaching, the density of photopigment was measured for 7 minutes by a test spot of 562 nm in wavelength and 1 degree in diameter, focussed on the fovea. Two-way density and the time constant of pigment regeneration were calculated. No significant difference was found in two-way density between the two groups. The time constant in high myopia (161.6 +/- 36.6 sec), however, was significantly increased (p < 0.01), compared with normals (124.0 +/- 28.7 sec). To study the correlation of psychophysical visual function, we performed a photostress recovery test, which revealed a significant delay of the recovery time in high myopia (p < 0.01). These results suggest that a delay in foveal cone pigment kinetics precedes loss of cone cells or chorioretinal degeneration in high myopia.

[Visual functions of dominantly inherited juvenile optic atrophy]

Visual functions including color vision and spectral sensitivity were investigated in 18 of 36 patients and in 2 persons with normal visual acuity in 8 families with dominantly inherited juvenile optic atrophy. Seven of the 8 families had at least one member who showed mainly acquired blue-yellow color vision deficiency. However, only 4 patients showed typical blue-yellow color vision deficiency, which suggested nonspecific characteristics of color vision deficiency in optic neural diseases. One family showed mainly acquired red-green color vision deficiency. Spectral sensitivity functions measured in 5 patients of 3 families showed sensitivity loss in the middle and long wavelength range as well as markedly decreased sensitivity in the short wavelength range. Decrease in spectral sensitivity in the short wavelength range or minimal blue-yellow color vision defect in a subject's brothers with normal visual acuity is interesting, but further study is needed because blue sensitivity decreases easily in various conditions.

[Foveal cone densitometer and changes in foveal cone pigments with aging]

A foveal cone densitometer was built for measuring the kinetics of foveal cone pigments in human eyes. The light from a 500-W xenon lamp was divided into reference, measuring, and bleaching beams, and projected through an optical fiber leading to a modified fundus camera. After the light was projected into the ocular fundus, the reflected light (central 1 degree) was measured by a photomultiplier and the regeneration time and the two-way density were abstracted from the records. The two-way density, which is the decadic logarithm of the measuring-reference beam ratio under bleached conditions divided by the measuring-reference beam ratio under dark conditions, eliminated the artifacts caused by eye movement of blink. Reliable curves were obtained in 45 eyes out of 53 healthy Japanese subjects (age range, 9 to 82 years). The mean +/- standard deviation SD of the two-way density (log) and the time constant (sec) were 0.34 +/- 0.09 and 139.9 +/- 79.3, respectively. The time constant significantly increased with aging.