Nonreciprocal Transmission and Reflection of a Chirally Coupled Quantum Dot

We report strongly nonreciprocal behavior for quantum dot exciton spins coupled to nanophotonic waveguides under resonant laser excitation. A clear dependence of the transmission spectrum on the propagation direction is found for a chirally coupled quantum dot, with spin up and spin down exciton spins coupling to the left and right propagation directions, respectively. The reflection signal shows an opposite trend to the transmission, which a numerical model indicates is due to direction-selective saturation of the quantum dot. The chiral spin-photon interface we demonstrate breaks reciprocity of the system and opens the way to spin-based quantum optical components such as optical diodes and circulators in a chip-based solid-state environment.

Prenatal transportation stress alters temperament and serum cortisol concentrations in suckling Brahman calves

This experiment examined the relationship between prenatal stress and subsequent calf temperament through weaning. The prenatal stressor used was repeated transportation of pregnant Brahman cows for 2 h at 60 ± 5, 80 ± 5, 100 ± 5, 120 ± 5, and 140 ± 5 d of gestation. Prenatally stressed calves ( = 41) were compared with controls ( = 44; dams did not undergo transportation during pregnancy) from 2 wk of age until weaning (average age at weaning = 174.8 ± 1.3 d). Temperament was defined by pen score (PS; 1 = calm and 5 = excitable), exit velocity (EV; m/sec), and temperament score (TS; (PS + EV)/2) and was recorded for each calf on d -168, -140, -112, -84, -56, -28, and 0 relative to weaning (d 0 = weaning). Cortisol concentrations were determined in serum samples obtained on d -168, -140, -28, and 0 relative to weaning. Birth weight and weaning weight were not different between treatment groups ( > 0.1). Pen score was greater ( = 0.03) in prenatally stressed calves (2.84 ± 0.21) relative to controls (2.31 ± 0.21). Exit velocity was greater ( < 0.01) in prenatally stressed calves (2.1 ± 0.14 m/sec) than in controls (1.61 ± 0.14 m/sec). Exit velocity was affected by a treatment × calf sex interaction ( = 0.04) and was greater in prenatally stressed females. Exit velocity was also affected by day ( < 0.0001). Temperament score was greater ( = 0.01) in prenatally stressed calves (2.45 ± 0.16) than in controls (1.95 ± 0.16). Temperament score was affected by day ( < 0.01). Basal cortisol concentrations were greater ( = 0.04) in prenatally stressed calves (15.87 ± 1.04 ng/mL) than in controls (13.42 ± 1.03 ng/mL). Basal cortisol concentrations were greater ( < 0.01) in females (16.61 ± 1.06 ng/mL) than in males (12.68 ± 1.02 ng/mL). Cortisol concentrations were positively correlated ( < 0.01) with PS ( = 0.55, < 0.01), EV ( = 0.4, < 0.01), and TS ( = 0.55, < 0.01). Overall, suckling Brahman calves that were prenatally stressed were more temperamental and had greater circulating serum concentrations of cortisol than control calves.

Physiological and metabolic responses of gestating Brahman cows to repeated transportation

This study characterized physiological responses to repeated transportation (TRANS) of gestating cows of differing temperaments. Cows were classified as Calm (C; = 10), Intermediate (I; = 28), or Temperamental (T; = 10). Based on artificial insemination date and pregnancy confirmation, cows were TRANS for 2 h on d 60 (TRANS1), 80 (TRANS2), 100 (TRANS3), 120 (TRANS4), and 140 (TRANS5) ± 5 d of gestation. Indwelling vaginal temperature (VT) monitoring devices were inserted 24 h before each TRANS with VT recorded from 2 h before TRANS and averaged into 5-min intervals through 30 min after TRANS. Serum samples were collected before loading and on unloading from the trailer to determine concentrations of cortisol, glucose, and nonesterified fatty acids (NEFA). Data were analyzed by repeated measures analysis in SAS. Serum cortisol concentrations were affected by temperament ( < 0.001), with T cows having the greater concentrations of cortisol before each TRANS event. All cows (100%) regardless of temperament exhibited elevations in cortisol following each TRANS event. Peak VT was greater ( < 0.001) at TRANS1 relative to all other TRANS events regardless of cow temperament. During TRANS, the T cows tended ( < 0.09) to have greater peak VT (39.86 ± 0.15°C) compared to C (39.41 ± 0.16°C) and I cows (39.55 ± 0.08°C). Area under the VT curve decreased ( = 0.002) from TRANS1 through TRANS5. Pre-TRANS serum glucose concentration at TRANS1 was greater ( < 0.03) for T (68.13 ± 4.31mg/dL) compared to I (53.42 ± 2.78 mg/dL) and C cows (52.76 ± 4.60 mg/dL). The C and I cows had greater changes in NEFA concentration between pre- and post-transport, and T cows showed the least change ( < 0.001). Cow VT and serum glucose concentration decreased in all temperaments ( < 0.01) with repeated TRANS; however, serum NEFA concentration post-TRANS did not vary ( > 0.10) with repeated TRANS events. Serum glucose concentrations were affected ( < 0.02) by a TRANS event by temperament interaction with T cows taking more TRANS events to decrease their change in glucose concentration compared to C and I cows. These results demonstrate that temperament influences physiological responses to stress in gestating Brahman cows. Although repeated transport in our study is confounded with day of gestation, seasonal changes, and learning from repeated handling and transport, repeated transport is a useful model of repeated stress in studying the effects of temperament.

Histone modifications on the adrenergic induction of type II deiodinase in rat pinealocytes

Histone modifications have been shown to play an important role in regulating gene expression. In this study, we investigated the impact of histone modifications on the adrenergic-regulated transcription of type 2 deiodinase (Dio2), a CREB-target gene in the rat pinealocyte. Treatment of pinealocytes with inhibitors of aurora C, a histone kinase, resulted in an inhibitory effect on the adrenergic-stimulated histone H3 Ser10 phosphorylation and Dio2 transcription. Given the established link between histone phosphorylation and acetylation, the role of histone acetylation on the adrenergic-induced Dio2 transcription was investigated. Treatment of pinealocytes with histone deacetylase inhibitors inhibited the adrenergic-induced Dio2 transcription. Chromatin immunoprecipitation with antibodies against acetylated Lys14 of H3 showed an increase in DNA recovery of the promoter region of Dio2 following treatment with trichostatin A. Together, our results indicate that, beside activation of CREB, epigenetic factors such as histone modifications also play an important role in regulating Dio2 transcription.

Salt-inducible kinase 1 in the rat pinealocyte: adrenergic regulation and role in arylalkylamine N-acetyltransferase gene transcription

The recognition of the basic leucine zipper domain in the regulation of transcriptional activity of cAMP response element-binding protein by salt-inducible kinase (SIK) prompted our investigation of the regulatory role of this kinase in the induction of Aa-nat and other cAMP-regulated genes in the rat pineal gland. Here we report Sik1 expression was induced by norepinephrine (NE) in rat pinealocytes primarily through activation of beta-adrenergic receptors, with a minor contribution from activation of alpha-adrenergic receptors. Treatments with dibutyryl cAMP, and to a lesser extent, agents that elevate intracellular Ca(2+) mimicked the effect of NE on Sik1 expression. In parallel to the results of the pineal cell culture studies, a marked nocturnal induction of Sik1 transcription was found in whole-animal studies. Knockdown of Sik1 by short hairpin RNA amplified the NE-stimulated Aa-nat transcription and other adrenergic-regulated genes, including Mapk phosphatase 1, inducible cAMP repressor, and type 2 iodothyronine deiodinase in a time-dependent manner. In contrast, overexpressing Sik1 had an inhibitory effect on the NE induction of Aa-nat and other adrenergic-regulated genes. Together, our results indicate that the adrenergic induction of Sik1 in the rat pineal gland is primarily through the beta-adrenergic receptor --> protein kinase A pathway. SIK1 appears to function as part of an endogenous repressive mechanism that regulates the peak and indirectly the duration of expression of Aa-nat and other cAMP-regulated genes. These findings support a role for SIK1 in framing the temporal expression profile of Aa-nat and other adrenergic-regulated genes in the rat pineal gland.

Opposite Effects of Proteasome Inhibitors in the Adrenergic Induction of ArylalkylamineN‐acetyltransferase in Rat Pinealocytes

In the rat pineal gland, the steady-state level of arylalkylamine N-acetyltransferase (AANAT) protein is controlled by transcriptional and translational mechanisms as well as by proteasome-mediated degradation. Studies with proteasome inhibitors, MG132 and clasto-lactacystin beta-lactone (c-lact), show two opposite effects of proteasomal inhibition on norepinephrine (NE)-induction of Aanat. Addition of MG132 or c-lact following NE stimulation causes an increase in AANAT protein level and enzyme activity without affecting the level of Aanat mRNA. In contrast, addition of inhibitors prior to NE stimulation reduces the NE-stimulated Aanat mRNA, AANAT protein, and enzyme activity. The inhibitory effect of proteasomal inhibition on adrenergic-induced Aanat transcription appears specific for Aanat because it has no effect on the adrenergic induction of mitogen-activated protein kinase phosphatase-1 (mkp-1). The effects of the proteasome inhibitors on NE-stimulated Aanat induction appear to be mediated by accumulation of a protein repressor.

Nocturnal activation of aurora C in rat pineal gland: its role in the norepinephrine-induced phosphorylation of histone H3 and gene expression

We have shown previously that Ser10 phosphorylation of histone H3 occurs in rat pinealocytes after stimulation with norepinephrine (NE) and that histone modifications such as acetylation appear to play an important role in pineal gene transcription. Here we report the nocturnal phosphorylation of a Ser10 histone H3 kinase, Aurora C, in the rat pineal gland. The time profile of this phosphorylation parallels the increase in the level of phospho-Ser10 histone H3. Studies with cultured pinealocytes indicate that Aurora C phosphorylation is induced by NE and this induction can be blocked by cotreatment with propranolol or KT5720, a protein kinase A inhibitor. Moreover, only treatment with dibutyryl cAMP, but not other kinase activators, mimics the effect of NE on Aurora C phosphorylation. These results indicate that Aurora C is phosphorylated primarily by a beta-adrenergic/protein kinase A-mediated mechanism. Treatment with an Aurora C inhibitor reduces the NE-induced histone H3 phosphorylation and suppresses the NE-stimulated induction of arylalkylamine N-acetyltransferase (AA-NAT), the rhythm-controlling enzyme of melatonin synthesis, and melatonin production. The effects of Aurora C inhibitors on adrenergic-induced genes in rat pinealocytes are gene specific: inhibitory for Aa-nat and inducible cAMP repressor but stimulatory for c-fos. Together our results support a role for the NE-stimulated phosphorylation of Aurora C and the subsequent remodeling of chromatin in NE-stimulated Aa-nat transcription. This phenomenon suggests that activation of this mitotic kinase can be induced by extracellular signals to participate in the transcriptional induction of a subset of genes in the rat pineal gland.

Predicting beef tenderness using near-infrared spectroscopy1

The objective of this multiple-phase study was to determine the accuracy of an on-line near-infrared (NIR) spectral reflectance system to predict 14-d-aged cooked beef tenderness. In phase I, 292 carcasses (140 US Select, 152 US Choice) were selected (d 2) from 2 commercial beef processing facilities. After carcass selection, longissimus lumborum (LL) muscle sections (ribs 9 to 12) were individually identified, vacuum-packaged, and transported to the Oklahoma State University Meats Laboratory, where a 2.54-cm-thick steak (n = 1) was fabricated and stored in refrigerated conditions (1 degrees C +/- 1). Following a 30-min oxygenation period, a NIR spectral scan was obtained on the 12th-rib LL steak. Steaks (d 3) were individually vacuum-packaged and aged at 4 degrees C for a total of 14 d before cooking slice shear force (SSF) analysis. In phases II and III, 476 carcasses (258 US Select, 218 US Choice) were immediately NIR scanned after carcass presentation to in-plant USDA grading personnel. In a similar fashion, all LL steaks were aged (1 degrees C +/- 1) for 14 d before cooking (70 degrees C) and conducting SSF. Of the phase I and II samples, 39 (6.77%) were categorized as being tough (i.e., >/= 25 kg of SSF after the 14-d postmortem aging period). Of these 39 tough samples, 20 (3.7% error rate) were correctly placed in the 90% certification level. Another 10 tough samples were placed in the 80% certification level (2.0% error rate). The overall NIR certified tender group was 1.67 kg more tender (P < 0.05) than LL samples from the noncertified samples. When the NIR predicted samples to be tough, 10% of the samples were eliminated from the phase I and II LL populations at 90% certification. The population SSF mean improved in excess of 6.5 kg. For phase III, SSF evaluation by an independent third party indicated the NIR system was able to successfully sort tough from tender LL samples to 70% certification levels. It was concluded that NIR scanning offers an in-plant opportunity to sort carcasses into tenderness outcome groups for guaranteed-tender branded beef programs.

Acetylation of histone H3 and adrenergic-regulated gene transcription in rat pinealocytes

In this study we investigated the effect of histone acetylation on the transcription of adrenergic-induced genes in rat pinealocytes. We found that treatment of pinealocytes with trichostatin A (TSA), a histone deacetylase inhibitor, caused hyperacetylation of histone H3 (H3) Lys14 at nanomolar concentrations. Hyperacetylation of H3 was also observed after treatment with scriptaid, a structurally unrelated histone deacetylase inhibitor. The effects of TSA and scriptaid were inhibitory on the adrenergic induction of arylalkylamine-n-acetyltransferase (aa-nat) mRNA, protein, and enzyme activity, and on melatonin production. TSA at higher concentrations also inhibited the adrenergic induction of mapk phosphatase-1 (mkp-1) and inducible cAMP early repressor mRNAs. In contrast, the effect of TSA on the norepinephrine induction of the c-fos mRNA was stimulatory. Moreover, the effect of TSA on adrenergic-induced gene transcription was dependent on the time of its addition; its effect was only observed during the active phase of transcription. Chromatin immunoprecipitation with antibodies against acetylated Lys14 of H3 showed an increase in DNA recovery of the promoter regions of aa-nat, mkp-1, and c-fos after treatment with TSA. Together, our results demonstrate that histone acetylation differentially influences the transcription of adrenergic-induced genes, an enhancing effect for c-fos but inhibitory for aa-nat, mkp-1, and inducible cAMP early repressor. Moreover, both inhibitory and enhancing effects appear to be mediated through specific modification of promoter-bound histones during gene transcription.

The role of repressor proteins in the adrenergic induction of type II iodothyronine deiodinase in rat pinealocytes

In this study, we investigated the transcriptional regulation of the adrenergic induction of type II iodothyronine deiodinase (Dio2) in rat pinealocytes. Treatment of pinealocytes with norepinephrine (NE) caused an increase in the mRNA level of Dio2 that peaked around 2 h and declined over the next 5 h. Both beta- and alpha1-adrenergic receptors contributed to the NE induction of Dio2 expression through a cAMP/protein kinase A mechanism. In pinealocytes that had been stimulated by NE, inhibition of transcription by actinomycin had no discernible effect on Dio2 expression. In contrast, inhibition of protein synthesis by cycloheximide enhanced the NE induction of Dio2 expression, suggesting the involvement of a repressor protein. Transient transfection of pinealocytes with adenovirus expressing small interfering RNA against Fos-related antigen 2 (Fra2) enhanced the NE induction of Dio2 expression, whereas the effect of overexpression of the full-length transcript of Fra2 was inhibitory. Time-course study indicated that preventing the NE induction of Fra2 enhanced the NE induction of Dio2 after 3 h, and the enhancement persisted beyond 6 h after NE stimulation. In comparison, transient transfection of pinealocytes with small interfering RNA against inducible cAMP early repressor (Icer) had no effect on the NE induction of Dio2 expression, whereas overexpression of the full-length transcript of Icer caused a small reduction of the NE-stimulated Dio2 expression. Together, our results support Fra-2 as an important transcriptional repressor that helps shape the time profile of the adrenergic induction of Dio2 expression in the rat pineal gland.

Mitogen-activated protein kinase phosphatase-1 (MKP-1) preferentially dephosphorylates p42/44MAPK but not p38MAPK in rat pinealocytes

We recently reported a diurnal and norepinephrine (NE) -induced expression of mitogen-activated protein kinase (MAPK) phosphatase-1 (MKP-1) in the rat pineal gland and postulated that this MKP-1 expression might impact adrenergic-regulated arylalkylamine-N-acetyltransferase (AA-NAT) activity via modulation of MAPKs. In this study, we investigated the effect of depletion of MKP-1 expression by using doxorubicin, a topoisomerase inhibitor that suppresses the expression of MKP-1 in other cell types and small interfering RNA targeted against Mkp1 in NE-stimulated pinealocytes. We found that both treatments were effective in inhibiting NE induction of MKP-1 expression. Moreover, both treatments also resulted in a prolonged activation of p42/44MAPK and an increase in AA-NAT induction by NE. In contrast, treatment of pinealocytes with PD98059, an inhibitor of MAPK kinase, reduced NE-stimulated AA-NAT activity. Interestingly, suppressing MKP-1 expression had no effect on the time profile of NE-stimulated p38MAPK activation. These results indicate that MKP-1 modulates the profile of AA-NAT activity by selectively shaping the activation profile of p42/44MAPK but not that of p38MAPK.

Histone H3 phosphorylation in the rat pineal gland: adrenergic regulation and diurnal variation

In this study, we investigated phosphorylation of Ser10 in histone H3 by norepinephrine (NE) in the rat pineal gland. In whole-animal studies, we demonstrated a marked increase in histone H3 phosphorylation in the rat pineal gland during the first half of the dark period. Exposure to light during this period caused a rapid decline in histone H3 phosphorylation with an estimated t1/2 of less than 15 min, indicating a high level of dephosphorylation activity. Corresponding studies in cultured pineal cells revealed that treatment with NE produced an increase in histone H3 phosphorylation that peaked between 2 and 3 h and declined rapidly by 4 h. The NE-induced histone H3 phosphorylation was blocked by cotreatment with propranolol or KT5720, a protein kinase A inhibitor, but not by prazosin or other kinase inhibitors. Moreover, only treatment with dibutyryl cAMP but not other kinase activators mimicked the effect of NE on histone H3 phosphorylation. The NE-stimulated H3 phosphorylation was markedly increased by cotreatment with a serine/threonine phosphatase inhibitor, tautomycin or okadaic acid, supporting a high level of ongoing histone H3 dephosphorylation activity. Together, our results indicate that histone H3 phosphorylation is a naturally occurring event at night in the rat pineal gland that is driven almost exclusively by a NE-->beta-adrenergic-->cAMP/protein kinase A signaling mechanism. This transient histone H3 phosphorylation probably reflects the nocturnal activation of multiple adrenergic-regulated genes in the rat pineal gland.

The role of inducible repressor proteins in the adrenergic induction of arylalkylamine-N-acetyltransferase and mitogen-activated protein kinase phosphatase-1 in rat pinealocytes

In this study, we investigated the role of two inducible repressor proteins, inducible cAMP early repressor (ICER) and Fos-related antigen 2 (Fra-2) in the adrenergic induction of MAPK phosphatase-1 (MKP-1) as compared with their roles in the induction of arylalkylamine-N-acetyltransferase (AA-NAT) in rat pinealocytes. Treatment of pinealocytes with norepinephrine (NE) caused an increase in the mRNA and protein levels of MKP-1 and AA-NAT, as well as in the AA-NAT activity and melatonin production. NE stimulation also caused a simultaneous increase in the mRNA and protein levels of ICER and Fra-2. Transient knockdown of icer using adenovirus expressing small interfering RNA (siRNA) abolished the NE induction of icer expression but had little effect on the NE induction of mkp-1 or aa-nat expression. In contrast, pretreatment with adenovirus overexpressing icer was effective in reducing the NE induction of mkp-1 and aa-nat. The inhibitory effect of overexpressing icer was reversed by cotreatment with siRNA against icer. siRNA against fra-2 also abolished the NE-stimulated expression of fra-2 but had little effect on the NE induction of mkp-1 and aa-nat expression. Proteasomal inhibition, which reduced the NE-stimulated induction of aa-nat, caused a reduction of ICER and Fra-2. Together, these results indicate that whereas overexpression of ICER can suppress the NE induction of aa-nat and mkp-1, the amount of the repressors, ICER and Fra-2, present during NE induction appears insufficient to exert a significant effect in controlling the expression of these genes.

The role of protein turnover in regulating MKP-1 levels in rat pinealocytes

We have previously shown that mitogen-activated protein kinase (MAPK) phosphatase-1 (MKP-1) is induced at night under the control of a photoneural system in the rat pineal gland. Because of the established roles of MAPKs, glucocorticoids and proteasome activity in regulating MKP-1 expression in other cell types, their relative contributions to MKP-1 regulation were investigated in rat pinealocytes. We found that neither inhibition of MAPKs nor treatment with dexamethasone affected norepinephrine-stimulated MKP-1 expression. In contrast, treatment with proteasome inhibitors increased norepinephrine-stimulated MKP-1 protein levels and abolished the decline in norepinephrine-stimulated MKP-1 protein levels caused by inhibition of transcription or translation, or blockade of alpha-adrenergic receptors. Taken together, our results indicate that in rat pinealocytes, the continuous and rapid turnover of MKP-1 protein allows for its rapid induction but is not sufficient to generate the sustained increase in MKP-1 expression post-adrenergic stimulation.

Timing of mitogen-activated protein kinase (MAPK) activation in the rat pineal gland

Activation of members of the mitogen-activated protein kinase (MAPK) family of signaling cascades is a tightly controlled event in rat pinealocytes. Cell culture studies indicate that whereas the NE-->cGMP activation of p42/44MAPK is rapid and transient, the NE-->cAMP activation of p38MAPK is slower and more sustained. The decline in the p42/44MAPK response is in part due to the induction of MAPK phosphatase-1 by NE. In comparison, p38MAPK activation is tightly coupled to the synthesis and degradation of an upstream element in its activation cascade. Whole animal studies confirm activation of p42/44MAPK occurring during the early part of night and precedes p38MAPK activation. Studies with selective MAPK inhibitors reveal a modulating effect of MAPKs on arylalkylamine-N-acetyltransferse (AA-NAT) activity, with involvement of p42/44MAPK in the induction of AA-NAT and p38MAPK participating in the amplitude and duration of the AA-NAT response. These effects of p42/44MAPK and p38MAPK on AA-NAT activity match their timing of activation. Taken together, our studies on the timing of MAPK activation and regulation of AA-NAT by MAPKs add to the importance of MAPKs in regulating the circadian biology of the pineal gland.

Proteasomal proteolysis in the adrenergic induction of arylalkylamine-N-acetyltransferase in rat pinealocytes

In this study, we investigated the effect of proteasomal inhibition on the induction of arylalkylamine-N-acetyltransferase (AA-NAT) enzyme in cultured rat pinealocytes, using two proteasome inhibitors, MG132 and clastolactacystin beta-lactone (c-lact). Addition of c-lact or MG132 3 h after norepinephrine (NE) stimulation produced a significant increase in AA-NAT protein level and enzyme activity. However, when the proteasome inhibitors were added before or together with NE, significant reductions of the NE-induced aa-nat mRNA, protein, and enzyme activity were observed. A similar inhibitory effect of MG132 on aa-nat transcription was observed when cells were stimulated by dibutyryl cAMP, indicating an effect distal to a post-cAMP step. The inhibitory effect of MG132 on adrenergic-induced aa-nat transcription was long lasting because it remained effective after 14 h of washout and appeared specific for aa-nat because the induction of another adrenergic-regulated gene, MAPK phosphatase-1, by NE was not affected. Time-profile studies revealed that the inhibitory effect of MG132 on NE-stimulated aa-nat induction was detected after 1 h, suggesting accumulation of a protein repressor as a possible mechanism of action. This possibility was also supported by the finding that the inhibitory effect of c-lact on NE-induced aa-nat induction was markedly reduced by cycloheximide, a protein synthesis inhibitor. Together, these results support an important role of proteasomal proteolysis in the adrenergic-mediated induction of aa-nat transcription through its effect on a protein repressor.

Role of protein turnover in the activation of p38 mitogen-activated protein kinase in rat pinealocytes

Differences in the time profiles of activation between p38MAPK and p42/44MAPK by norepinephrine (NE) in rat pinealocytes suggest involvement of mechanisms other than the phosphorylation cascades in their activation. In the present study we investigated whether protein turnover played a role in regulating p38MAPK activation in the rat pineal gland. NE stimulation caused an increase in MAPK kinase3/6 (MKK 3/6) and p38MAPK phosphorylation that occurred in the absence of changes in the mRNA or protein levels of p38MAPK or MKK3/6. The stimulatory effect of NE on phosphorylated MKK3/6 and p38MAPK, but not phosphorylated p42/44MAPK, was blocked by treatment with actinomycin or cycloheximide, indicating a requirement of transcription and translation in activation of the p38MAPK but not the p42/44MAPK pathway. Moreover, inhibition of proteasomes by clasto-lactacystin beta-lactone or Z-Leu-Leu-Leu-CHO (MG132) selectively increased basal and NE-stimulated phosphorylated MKK3/6 and p38MAPK levels without affecting the mRNA or protein levels of MKK3 or p38MAPK. In contrast, the effect of proteasomal inhibition on NE-stimulated p42/44MAPK phosphorylation was inhibitory. Treatment with MG132 also reduced the decline in the phosphorylated levels of NE-stimulated MKK3/6 and p38MAPK that normally follows beta-adrenergic blockade. Together, our results indicate that p38MAPK but not p42/44MAPK activation in the rat pineal gland is tightly coupled to protein synthesis and degradation. The synthesis of an activator upstream of MKK3/6 is required for the NE-activation of p38MAPK.

Mitogen-activated protein kinase phosphatase-1 (MKP-1): >100-fold nocturnal and norepinephrine-induced changes in the rat pineal gland

The norepinephrine-driven increase in mitogen-activated protein kinase (MAPK) activity is part of the mechanism that regulates arylalkylamine N-acetyltransferase (AA-NAT) activity in the rat pineal gland. We now report a marked nocturnal increase in the expression of a MAPK phosphatase, MAP kinase phosphatase-1 (MKP-1), that was blocked by maintaining animals in constant light or treatment with propranolol. MKP-1 expression was regulated by norepinephrine acting through both alpha- and beta-adrenergic receptors. These results establish a nocturnal increase in pineal MKP-1 expression that is under the control of a photoneural system. Because substrates of MKP-1 can influence AA-NAT activity, our findings suggest the involvement of MKP-1 in the regulation of the nocturnal AA-NAT signal.

Norepinephrine induction of mitogen-activated protein kinase phosphatase-1 expression in rat pinealocytes: distinct roles of alpha- and beta-adrenergic receptors

In this study, we investigated the mechanisms through which norepinephrine (NE) regulates MAPK phosphatase-1 (MKP-1) expression in rat pinealocytes. Stimulation with NE (a mixed alpha- and beta-adrenergic agonist) caused a rapid increase in MKP-1 mRNA and protein that peaked around 1 h post stimulation, and the response was sustained for at least 4 h. Selective activation of beta-adrenergic receptors with isoproterenol for 1 h caused a similar increase in MKP-1 mRNA and protein as observed with NE, but at 3 h, the isoproterenol response was much lower relative to NE. In contrast, selective activation of alpha-adrenergic receptors caused only small increases in MKP-1 mRNA and protein and appeared to function primarily in prolonging the beta-adrenergic-stimulated responses. In NE-stimulated pinealocytes, blockade of beta-adrenergic receptors caused a rapid reduction in MKP-1 mRNA, but it had a minimal effect on MKP-1 protein. In contrast, blockade of alpha-adrenergic receptors specifically reduced NE-induced MKP-1 protein but not mRNA. At the postreceptor level, treatment with dibutyryl cAMP caused parallel increases in MKP-1 mRNA and protein. However, treatment with a protein kinase C activator caused a significant increase in MKP-1 protein but had little effect on MKP-1 mRNA. Together, these results suggest that, in rat pinealocytes, NE activates the beta-adrenergic receptor --> protein kinase A pathway to induce transcription and translation of MKP-1 expression and the alpha-adrenergic receptor --> protein kinase C pathway to prolong the stimulated responses through increased stability of the MKP-1 protein.

Inhibition of p38 mitogen-activated protein kinase enhances adrenergic-stimulated arylalkylamine N-acetyltransferase activity in rat pinealocytes

We have previously shown that inhibition of p38(MAPK) increases adrenergic-stimulated p42/44(MAPK) activation in rat pinealocytes. In this study we investigated whether p38(MAPK) played a role in the adrenergic regulation of arylalkylamine-N-acetyltransferase (AA-NAT) induction and melatonin (MT) synthesis. Treatment of pinealocytes with norepinephrine (NE) caused a time-dependent increase in the levels of AA-NAT mRNA, AA-NAT protein, and enzymatic activity as well as MT production. Cotreatment with SB202190, a selective p38(MAPK) inhibitor, although having no effect on AA-NAT activity or protein level 3 h after NE treatment, caused a sustained increase in AA-NAT activity and protein level after 6 h of NE treatment. The increases in NE-stimulated AA-NAT activity and protein level by SB202190 occurred in the absence of an increase in AA-NAT mRNA. Similar results were obtained when AA-NAT was induced by (Bu)(2)cAMP or when SB203580 was used to inhibit p38(MAPK). In comparison, SB202474, the inactive analog, had no effect on NE or (Bu)(2)cAMP-stimulated AA-NAT activity or protein level. SB202190 also increased cumulative NE-stimulated MT production, provided that the medium was supplemented with 5-methoxytryptamine. p38(MAPK) inhibitors had no effect on hydroxyindole-O-methyltransferase activity. These results show that inhibition of p38(MAPK), although having no effect on cAMP-mediated AA-NAT transcription, appears to increase AA-NAT activity either by increasing translation or by reducing degradation of the AA-NAT protein. The lack of effect on NE-stimulated MT accumulation by p38(MAPK) inhibitors in the absence of 5-methoxytryptamine could be secondary to a lack of substrate, or alternatively, hydroxyindole-O-methyltransferase may become limiting.

Ectopic expression of the Drosophila Cdk1 inhibitory kinases, Wee1 and Myt1, interferes with the second mitotic wave and disrupts pattern formation during eye development

Wee1 kinases catalyze inhibitory phosphorylation of the mitotic regulator Cdk1, preventing mitosis during S phase and delaying it in response to DNA damage or developmental signals during G2. Unlike yeast, metazoans have two distinct Wee1-like kinases, a nuclear protein (Wee1) and a cytoplasmic protein (Myt1). We have isolated the genes encoding Drosophila Wee1 and Myt1 and are using genetic approaches to dissect their functions during normal development. Overexpression of Dwee1 or Dmyt1 during eye development generates a rough adult eye phenotype. The phenotype can be modified by altering the gene dosage of known regulators of the G2/M transition, suggesting that we could use these transgenic strains in modifier screens to identify potential regulators of Wee1 and Myt1. To confirm this idea, we tested a collection of deletions for loci that can modify the eye overexpression phenotypes and identified several loci as dominant modifiers. Mutations affecting the Delta/Notch signaling pathway strongly enhance a GMR-Dmyt1 eye phenotype but do not affect a GMR-Dwee1 eye phenotype, suggesting that Myt1 is potentially a downstream target for Notch activity during eye development. We also observed interactions with p53, which suggest that Wee1 and Myt1 activity can block apoptosis.

Under the radar: contributions of the SUPPORT nurses

SUPPORT (The Study to Understand Prognoses and Preferences for Outcomes and Risks of Treatment) failed to produce changes in 5 quantitative outcome measures of care received by nearly 10,000 seriously ill patients in major teaching hospitals. This article reports a content analysis of documents produced during the SUPPORT study by the 17 nurses who delivered the intervention. "Effective communication" emerged as the central category, with "educational support" and "emotional support" as subcategories. "Readiness" of patients and families to accept prognoses, engage in decision making, and the like also arose from this analysis as an important concept. The investigation suggests that the SUPPORT intervention did have an important impact, albeit not one captured by the main effects analysis.

Discrimination of polymorphic forms of a drug product by localized thermal analysis

In chemical processing, it is important to distinguish between and identify polymorphic forms. We demonstrate the novel use of scanning thermal microscopy (SThM) and localized thermal analysis to distinguish and identify polymorphic forms of the drug cimetidine. These forms cannot be resolved by classical bulk thermal analysis. SThM reveals a sample consisting of a 50 : 50 mixture of the polymorphs contains regions of different thermal conductivity, corresponding to the different polymorphs. Localized thermal analysis of small volumes of pure polymorphic samples (approximately 50 microm3) shows that the origin of the thermal conductivity contrast lies, at least in part, with the presence of a surface water layer on the more hydrophilic polymorph.

An investigation into the use of micro-thermal analysis for the solid state characterisation of an HPMC tablet formulation

The use of micro-thermal analysis (microTA) as a novel means of differentiating between components in a model tablet formulation is described. This technique involves a modification of atomic force microscopy (AFM) such that the standard AFM tip is replaced with a Wollaston wire, thereby allowing the probe to act as a thermistor and temperature probe. Consequently it is possible to map not only the topology but also the thermal conductivity of the sample. Furthermore, it is possible to apply a heating signal to the material and thereby to perform thermal analysis on highly localised regions of the sample. Compacts were prepared comprising ibuprofen, HPMC E4M prem and 1:1 mixes of the two components and analysed using a microTA micro-thermal analyser. The surface topology and conductivity images of the three systems are reported. In addition, the ability of the technique to perform thermal analysis on highly specific regions of the sample is described. The method was able to differentiate between the components of the sample on the basis of micro-thermomechanical experiments. The implications of the use of the technique for the study of pharmaceutical tablets is discussed.

Micro-thermal analysis: scanning thermal microscopy and localised thermal analysis

Micro-thermal analysis combines the imaging capabilities of atomic force microscopy with the ability to characterise, with high spatial resolution, the thermal behaviour of materials. The conventional AFM tip is replaced by a miniature heater/thermometer which enables a surface to be visualised according to its response to the input of heat (in addition to measuring its topography). Areas of interest may then be selected and localised thermal analysis (modulated temperature calorimetry and thermomechanical analysis) carried out. Localised dynamic mechanical measurements are also possible. Spatially resolved chemical analysis can be performed using the same basic apparatus by means of pyrolysis gas chromatography-mass spectrometry or high-resolution photothermal infrared spectrometry.

Forgoing treatment in an adult with no apparent treatment preferences: a case report

This article reports in detail an ethics case consultation involving a decision to forgo life-sustaining treatment for a middle-aged man following a "massive" cerebral bleed resulting in profound brain damage, but not unconsciousness. An unusual feature of this case is that, despite normal intelligence, caring family relationships and a history of life-threatening cardiac disease, vigorous and sustained inquiry could not elicit any indications of this patient's values, perceptions or preferences regarding end of life care. Other than a deliberately autobiographical methodological prologue and a few brief comments at the end, the case is presented straightforwardly and without intercurrent analysis.

Empathy of intensive care nurses and critical care family needs assessment

In this study we explored the relationship between the empathy of intensive care unit (ICU) nurses and their ability to assess accurately the perceived needs of family members of patients hospitalized in ICU settings. Thirty family needs were studied by using Molter's 1983 revision of the Critical Care Family Needs Inventory (CCFNI). Data consisted of 92 pairs of CCFNI responses obtained from 92 family members of ICU patients and 60 ICU nurses providing direct care for these patients. Multiple regression analysis was performed to determine the extent to which empathy and nursing experience contribute to accurate assessment of the needs of ICU family members. The more emphatic ICU nurses were, the greater their ability to assess ICU family members' needs accurately on six of the needs studied (p less than or equal to 0.05). Length of nursing experience negatively affected the nurse's ability to assess three of the ICU family members' needs accurately (p less than 0.05).

Critical care family needs in an urban teaching medical center

This is a descriptive study of the relative importance of needs as reported by 213 family members of 114 patients hospitalized in critical care units of a large, urban, teaching, medical center. In this study we used Molter's Critical Care Family Needs Inventory (revised), an instrument that has been used in other similar investigations, but never before in such a large sample or one with similar demographics. In general, the findings were consistent with those in previous studies using the Critical Care Family Needs Inventory. One striking difference was the relatively low ranking accorded by this sample to the need "to feel there was hope." Parents, spouses, siblings, adult children, and "significant others" ranked their needs in strikingly similar ways. Family members of critically ill patients need two things most: to have honest, intelligible, and timely information and to feel assured that their loved one is being cared for by competent and caring people. Clinical, educational, and research implications are identified and briefly discussed.

Critical care family needs: nurse-family member confederate pairs

In this study we explored the relationship between critical care family members' perceived needs and the assessment of these needs by a confederate sample of intensive care unit (ICU) nurses. Family needs were measured by using Molter's revised Critical Care Family Needs Inventory. Data consisted of 92 confederate pairs of Critical Care Family Needs Inventory responses obtained from 92 family members of adult patients hospitalized in a variety of ICUs and 49 ICU nurses providing direct care for these patients. Paired t tests (two tailed) were calculated to detect significant differences between confederate pairs of family members' perceptions and ICU nurses' assessments of the importance of the needs studied. Family members' perceptions and ICU nurses' assessments of the most and least important critical care family needs were identified. Significant (p less than 0.001 to p less than 0.05) differences were detected between confederate pairs of family members' perceptions and ICU nurses' assessments of the importance of 15 (50%) of the critical care family needs studied. Therefore, it appears that these nurses were only moderately accurate in their assessments of critical care family needs. Implications for nursing practice, education, and research were identified and discussed.

New Jersey's "Granny Doe" squad: arguments about mechanisms for protection of vulnerable patients

A state government official in New Jersey has written to administrators of the state's nursing homes outlining what he understands to be certain implications of the Conroy, Peter and Farrell decisions of the New Jersey Supreme Court. These include mandatory reporting to and investigation by his office of virtually all cases of contemplated withholding or withdrawal of life-sustaining treatment, even decisions not to hospitalize or dialyze. This directive has aroused health professionals and advocates for patient privacy. The resulting urgent effort to fashion an acceptable alternative to decisional review by government agents is reminiscent of the process which was sparked by the federal government's promulgation of the "Baby Doe regulations" some years ago. Now, as then, a consensus is being fashioned by a wide spectrum of participants. The likely candidate for an alternative to "Granny Doe squads" is, once again, some form or forms of the institutional ethics committee. Any acceptable proposals will have to satisfy the requirement of public confidence in the face of a perception that elderly nursing home patients are particularly vulnerable to "abuse." They should, in the view of these participants in the debate, also acknowledge relevant differences among nursing homes and enhance, rather than discourage, the exercise of responsibility by nursing home leaders and staff members.

Emotional depletion in critical care staff

The cumulative effect of multiple patient deaths upon critical care staff may lead to emotional depletion and spiritual exhaustion. Attitudinal, behavioral, and social factors which contribute to such effects are examined. These factors include unresolved grief, the need to be perfect, projection of one's own needs, overseriousness, lack of sharing, inappropriate sharing at home, norms of solemnity, lack of structured opportunities for sharing, and administrative non-responsiveness. Empirical research to further define the nature and etiology of "staff burnout" is a logical, but most difficult, next step.

Transmitting balanced translocation carrier information within families: a follow-up study

Approximately 1 of 500 individuals is a carrier of a balanced chromosome translocation. Since many translocations are inherited, many (but not all) relatives of carriers have a need to be informed of their potential carrier status. Presently, no data are available as to what extent individuals identified as balanced carriers inform at-risk relatives of the problem. We interviewed 12 balanced translocation carriers to learn whether such information had been transmitted to relatives. The 12 propositi had 36 surviving sibs and 21 surviving parents. Of the 36 sibs, 32 were informed of their risk. The four sibs not informed were from two families. Only 16 of the 32 informed sibs had subsequent carrier testing. Of the 21 surviving parents, 14 were told by their children of their carrier status; subsequently, three parent couples were tested. This survey provides data showing that individuals do not always disclose genetic risk information to relatives. Therefore, genetic professionals need to determine if they have a duty to transmit such information to at-risk relatives in light of the harm that may occur when information is withheld.

Staff burnout in the perspective of grief theory

The processes leading to staff burnout are poorly understood, due to the very term "burnout." It is a static term which refers explicitly to the end-stage or outcome of a process, rather than to the process itself. Grief theory is an attempt to explore the process of adaptation to high stress work, a process which, through some inadequacy or disorder, too often eventuates in burnout. Concepts of grieving seem suited to this purpose because (a) grief has undergone transformation from a static term to a process term in response to theoretical efforts of the last generation, and (b) burnout entails considerable loss and is, in part, a response to loss. Kavenaugh's concept of the grieving process is used as a framework for a brief description of adaptation to the stresses of professional work with dying person and their families.

Cyclic oculomotor paralysis

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