Palladium (II)-Catalyzed C-H Activation with Bifunctional Ligands: From Curiosity to Industrialization

In 2001, our curiosity to understand the stereochemistry of C-H metalation with Pd prompted our first studies in Pd(II)-catalyzed asymmetric C-H activation (RSC Research appointment: 020 7451 2545, Grant: RG 36873, Dec. 2002). We identified four central challenges: 1. poor reactivity of simple Pd salts with native substrates; 2. few strategies to control site selectivity for remote C-H bonds; 3. the lack of chiral catalysts to achieve enantioselectivity via asymmetric C-H metalation, and 4. low practicality due to limited coupling partner scope and the use of specialized oxidants. These challenges necessitated new strategies in catalyst and reaction development. For reactivity, we developed approaches to enhance substrate-catalyst affinity together with novel bifunctional ligands which participate in and accelerate the C-H cleavage step. For site-selectivity, we introduced the concept of systematically modulating the distance and geometry between a directing template, catalyst, and substrate to selectively access remote C-H bonds. For enantioselectivity, we devised predictable stereomodels for catalyst-controlled enantioselective C-H activation based on the participation of bifunctional ligands. Finally, for practicality, we have developed varied catalytic manifolds for Pd(II) to accommodate diverse coupling partners while employing practical oxidants such as simple peroxides. These advances have culminated in numerous C-H activation reactions, setting the stage for broad industrial applications.

A synthesis-enabled relative configurational assignment of the C31-C46 region of hemicalide

With 21 unknown stereocentres embedded in spatially separated stereoclusters, the cytotoxic polyketide hemicalide represents a seemingly intractible structural assignment problem. Herein, through the targeted synthesis of configurationally defined fragments, as...

Identification of CASZ1 NES reveals potential mechanisms for loss of CASZ1 tumor suppressor activity in neuroblastoma

As a transcription factor, localization to the nucleus and the recruitment of cofactors to regulate gene transcription is essential. Nuclear localization and nucleosome remodeling and histone deacetylase (NuRD) complex binding are required for the zinc-finger transcription factor CASZ1 to function as a neuroblastoma (NB) tumor suppressor. However, the critical amino acids (AAs) that are required for CASZ1 interaction with NuRD complex and the regulation of CASZ1 subcellular localization have not been characterized. Through alanine scanning, immunofluorescence cell staining and co-immunoprecipitation, we define a critical region at the CASZ1 N terminus (AAs 23-40) that mediates the CASZ1b nuclear localization and NuRD interaction. Furthermore, we identified a nuclear export signal (NES) at the N terminus (AAs 176-192) that contributes to CASZ1 nuclear-cytoplasmic shuttling in a chromosomal maintenance 1-dependent manner. An analysis of CASZ1 protein expression in a primary NB tissue microarray shows that high nuclear CASZ1 staining is detected in tumor samples from NB patients with good prognosis. In contrast, cytoplasmic-restricted CASZ1 staining or low nuclear CASZ1 staining is found in tumor samples from patients with poor prognosis. These findings provide insight into mechanisms by which CASZ1 regulates transcription, and suggests that regulation of CASZ1 subcellular localization may impact its function in normal development and pathologic conditions such as NB tumorigenesis.

Esophageal stenting for treatment of refractory benign esophageal strictures in dogs

BACKGROUND

Benign esophageal strictures can recur despite multiple dilatation procedures and palliative management can be challenging.

OBJECTIVE

To describe the technique and determine the outcome of esophageal stenting for treatment of refractory benign esophageal strictures (RBES) in dogs.

ANIMALS

Nine dogs with RBES.

METHODS

Retrospective review of records for dogs with RBES. Indwelling intraluminal esophageal stents were placed transorally with endoscopy, fluoroscopic guidance, or both. Follow-up information was obtained via medical record or telephone interview.

RESULTS

Nine dogs had 10 stents placed including biodegradable stents (BDS) (6/10), self-expanding metallic stents (SEMS) (3/10), and a self-expanding plastic stent (SEPS) (1/10). All dogs had short-term improved dysphagia. Complications included ptyalism, apparent nausea, gagging, vomiting, or regurgitation (8/9), confirmed recurrence of stricture (6/9), stent migration (3/9), stent shortening (1/9), megaesophagus (1/9), incisional infection (1/9), and tracheal-esophageal fistula (1/9). Eight of 9 dogs required intervention because of the complications of which 4 of 8 dogs were eventually euthanized because of stent-related issues. One dog was lost to follow-up examination.

CONCLUSIONS AND CLINICAL IMPORTANCE

Findings suggest that esophageal stent placement was safe and technically effective, but unpredictably tolerated in dogs with RBES. If a stent is placed, dogs should be monitored carefully for stent migration, dissolution of absorbable stents, and recurrence of strictures.

Placental abruption occurring soon after labor combined spinal-epidural analgesia

We present a case of placental abruption necessitating emergency cesarean section in an otherwise uncomplicated patient soon after initiation of combined spinal-epidural analgesia in labor. Administration of spinal opioids has the potential to cause fetal bradycardia due to uterine hypertonicity following rapid onset of analgesia. In this case, a previously bloody show before placement of combined spinal-epidural analgesia may have been evidence of a small abruption. We hypothesize that uterine hypertonicity following administration of spinal opioids may have hastened the development of an existing placental abruption.

Headaches and migraines are associated with an increased risk of preeclampsia in Peruvian women

BACKGROUND

Migraine, a common chronic-intermittent disorder of idiopathic origin characterized by severe debilitating headaches and autonomic nervous system dysfunction, and preeclampsia, a hypertensive disorder of pregnancy, share many common epidemiological and pathophysiological characteristics. Both conditions are associated with higher subsequent risk of ischemic stroke. Moreover, endothelial dysfunction, platelet activation, hyper-coagulation, and inflammation are common to both disorders. We assessed the risk for preeclampsia in relation to the maternal history of migraine before and during pregnancy in Peruvian women.

METHODS

Cases consisted of 339 women with preeclampsia, and controls were 337 normotensive women. During in-person interviews conducted at delivery, women were asked whether they had physician-diagnosed migraines, and they were asked questions that allowed for headaches and migraines to be classified according to criteria established by the International Headache Society (IHS). Logistic regression procedures were used to calculate odds ratios (ORs) and 95% confidence intervals (CIs).

RESULTS

A history of any headache before or during pregnancy was associated with a 2.4-fold increased risk for preeclampsia (OR = 2.4; 95% CI 1.7-3.3). Women classified as having migraines that began prior to pregnancy had a 3.5-fold increased risk for preeclampsia (95% CI 1.9-6.4) as compared with those who reported no migraines. Women with migraines during pregnancy had a fourfold increased risk of preeclampsia (OR = 4.0, 95% CI 1.9-8.2) compared with non-migraineurs.

CONCLUSIONS

Our findings are consistent with previous reports and we have extended them to the Peruvian population. Prospective cohort studies, however, are needed to more rigorously evaluate the extent to which migraines and/or its treatments are associated with the occurrence of preeclampsia.

Radiation dose from cone beam computed tomography for image-guided radiation therapy

PURPOSE

To perform a comprehensive study on organ absorbed doses and effective doses from cone beam computed tomography (CBCT) for three different treatment sites.

METHODS AND MATERIALS

An extensive set of dosimetric measurements were performed using a widely used CBCT system, the On-Board Imager (OBI). Measurements were performed using a female anthropomorphic phantom with thermoluminescent dosimeters (TLD). The effective doses to the body and the absorbed doses to 26 organs were reported using two different technical settings, namely, the standard mode and the low-dose mode. The measurements were repeated for three different scan sites: head and neck, chest, and pelvis. Comparisons of patient doses as well as image quality were performed among the standard mode CBCT, low-dose mode CBCT, and fan beam CT.

RESULTS

The mean skin doses from standard mode CBCT to head and neck, chest and pelvis were 6.7, 6.4, and 5.4 cGy per scan, respectively. The effective doses to the body from standard mode CBCT for imaging of head and neck, chest, and pelvis were 10.3, 23.7, and 22.7 mSv per scan, respectively. Patient doses from low-dose mode CBCT were approximately one fifth of those from standard mode CBCT.

CONCLUSIONS

Patient position verification by standard mode CBCT acquired by OBI on a daily basis could increase the secondary cancer risk by up to 2% to 4%. Therefore lower mAs settings for daily CBCT should be considered, especially when bony anatomy is the main interest.

Identification of sex chromosome molecular markers using RAPDs and fluorescent in situ hybridization in rainbow trout

The goal of this work is to identify molecular markers associated with the sex chromosomes in rainbow trout to study the mode of sex determination mechanisms in this species. Using the RAPD assay and bulked segregant analysis, two markers were identified that generated polymorphic bands amplifying preferentially in males of the Mount Lassen and Scottish strains of rainbow trout. Chromosomal localization using fluorescent in situ hybridization of a 900 bp probe developed from one of these markers revealed a brightly defined signal on a chromosome that could morphologically be classified as the Y chromosome.

A derivative of bovine herpesvirus 1 (BoHV-1) UL3.5 lacking the last forty amino acids inhibits replication of BoHV-1

Bovine herpesvirus 1 (BoHV-1) UL3.5 is a tegument protein that interacts with BoHV-1 alpha-transinducing factor alphaBTIF). In this report, we show that a truncated UL3.5 lacking the last 40 amino acids (C40UL3.5) inhibited replication of BoHV-1. Stable expression of C40UL3.5 in MDBK cells inhibited replication of BoHV-1 300- to 500-fold in plaque assays. This inhibitory effect was specific for BoHV-1 as cells expressing C40UL3.5 supported replication of pseudorabies virus (species Suid herpesvirus 1, SuHV-1) and herpes simplex virus (species Human herpesvirus 1, HHV-1) to normal levels. In contrast, a truncated UL3.5 which lacked the first 20 amino acids and did not interact with alphaBTIF did not inhibit BoHV-1 replication. In the C40UL3.5-expressing cells infected with BoHV-1, expression of the viral immediate early gene BICP4 and the early protein gB were reduced and delayed. C40UL3.5, when either transiently or stably expressed, inhibited alphaBTIF-mediated transactivation of a BoHV-1 immediate-early promoter. C40UL3.5 may be useful for constructing transgenic cattle resistant to infection by BoHV-1.

Patients with and without intellectual disability seeking outpatient psychiatric services: diagnoses and prescribing pattern

BACKGROUND

The present study examined the presenting problem of psychiatric outpatients, and resulting diagnostic and prescribing patterns, comparing patients with intellectual disability (ID) with non-ID (N-ID) patients seen in the same clinic.

METHODS

This study was a retrospective medical chart review of information in the first psychiatric diagnostic evaluation for the most recent 100 adult patients with mild ID, 100 patients with moderate, severe or profound ID, and 100 matching N-ID patients.

RESULTS

There were significant differences in rates of medical illness, disabilities, history of marriage, children, independent living, and family history of psychiatric and neurological disorders. Individuals with ID were more likely to present with aggression, self-injurious behaviour or physical complaints, whereas N-ID subjects presented more frequently with depression and anxiety complaints. For all groups, depressive disorders were the most frequent class of diagnoses. For those with ID, antipsychotics were used in 32% of subjects, with mood stabilizers in 28% and antidepressants in 27%. The N-ID subjects were most frequently prescribed antidepressants (40%) and anxiolytics (22%). Polypharmacy did not differ significantly among groups.

CONCLUSIONS

Psychiatric practitioners relied on the diagnostic examination to formulate their diagnosis, whereas the chief complaint reflected the view of caregivers of the subjects with ID. In contrast to previous studies, outpatient providers frequently diagnosed depression, and the prescribing pattern showed increased usage of antidepressants and mood stabilizers.

Characterization of sex chromosomes in rainbow trout and coho salmon using fluorescence in situ hybridization (FISH)

With the aim of characterizing the sex chromosomes of rainbow trout (Oncorhynchus mykiss) and to identify the sex chromosomes of coho salmon (O. kisutch), we used molecular markers OmyP9, 5S rDNA, and a growth hormone gene fragment (GH2), as FISH probes. Metaphase chromosomes were obtained from lymphocyte cultures from farm specimens of rainbow trout and coho salmon. Rainbow trout sex marker OmyP9 hybridizes on the sex chromosomes of rainbow trout, while in coho salmon, fluorescent signals were localized in the medial region of the long arm of one subtelocentric chromosome pair. This hybridization pattern together with the hybridization of a GH2 intron probe on a chromosome pair having the same morphology, suggests that a subtelocentric pair could be the sex chromosomes in this species. We confirm that in rainbow trout, one of the two loci for 5S rDNA genes is on the X chromosome. In males of this species that lack a heteromorphic sex pair (XX males), the 5S rDNA probe hybridized to both subtelocentrics. This finding is discussed in relation to the hypothesis of intraspecific polymorphism of sex chromosomes in rainbow trout.

Bovine herpesvirus 1 U(L)3.5 interacts with bovine herpesvirus 1 alpha-transinducing factor

The bovine herpesvirus 1 (BHV-1) U(L)3.5 gene encodes a 126-amino-acid tegument protein. Homologs of U(L)3.5 are present in some alphaherpesviruses and have 20 to 30% overall amino acid homology that is concentrated in the N-terminal 50 amino acids. Mutant pseudorabies virus lacking U(L)3.5 is deficient in viral egress but can be complemented by BHV-1 U(L)3.5 (W. Fuchs, H. Granzow, and T. C. Mettenleiter, J. Virol. 71:8886-8892, 1997). The function of BHV-1 U(L)3.5 in BHV-1 replication is not known. To get a better understanding of its function, we sought to identify the proteins that interact with the BHV-1 U(L)3.5 protein. By using an in vitro pull-down assay and matrix-assisted laser desorption ionization mass spectrometry analysis, we identified BHV-1 alpha-transinducing factor (alphaBTIF) as a BHV-1 U(L)3. 5-interacting protein. The interaction was verified by coimmunoprecipitation from virus-infected cells using an antibody to either protein, by indirect immunofluorescence colocalization in both virus-infected and transfected cells, and by the binding of in vitro-translated proteins. In virus-infected cells, U(L)3.5 and alphaBTIF colocalized in a Golgi-like subcellular compartment late in infection. In transfected cells, they colocalized in the nucleus. Deletion of 20 amino acids from the N terminus of U(L)3.5, but not 40 amino acids from the C terminus, abolished the U(L)3.5-alphaBTIF interaction both in vitro and in vivo. The interaction between U(L)3. 5 and alphaBTIF may be important for BHV-1 maturation and regulation of alphaBTIF transactivation activity.

Adrenaline upregulates monocyte L-selectin in vitro

OBJECTIVE

Although surface adhesion molecules mediate leucocyte-endothelial interactions at sites of inflammation, relatively little is known of the factors which increase the expression of L-selectin in circulating leucocytes. The expression of leucocyte L-selectin increases during acute stress events such as injury and is temporally related to an early neuroendocrine response. This study investigates whether adrenaline increases the expression of L-selectin on monocytes, neutrophils and lymphocytes in vitro and whether these effects are mediated via beta-adrenoceptors.

METHODS

A total of 20 ml of blood was withdrawn from 28 healthy volunteers (21 males) with a mean age of 29 years (range 23-67 years). Adrenaline at physiological doses mimicking trauma (0-200 nmol/l) was added to whole blood prior to immunofluorescent staining and analysis by flow cytometry. Propranolol (50 microl of 2 x 10(-5) M) was also added to separate tubes prior to incubation with adrenaline. Saline (40 microl 0.9% solution) was used as a control. Expression is described firstly as percentage of cells expressing L-selectin and secondly as average intensity (mean channel fluorescence, mcf) per cell expressing CD62L. Summary measures were used to analyse the data.

RESULTS

A significant increase in both the percentage of monocytes expressing L-selectin and mean channel fluorescence of L-selectin was evident with adrenaline in vitro (P < 0.0001). Maximal increases occurred at 100 nmol/l adrenaline when a 9% increase in the percentage of monocytes expressing L-selectin and a 23% increase in mean channel fluorescence were observed. These effects were both blocked by propranolol (P < 0.0001). No significant differences were observed for neutrophils or lymphocytes except for a slight increase in the percent neutrophils expressing L-selectin, and a small decreasing trend in percent lymphocytes expressing L-selectin.

CONCLUSIONS

Adrenaline upregulates the surface expression of L-selectin on monocytes in vitro, an effect which is partially mediated by beta-adrenoceptors. As monocytes initiate early aspects of the inflammatory response, these findings suggest that beta-blockade may have an inhibitory role for certain aspects of leucocyte trafficking.

Dealing with fatigue: the importance of health-related action patterns

Fatigue complaints are frequent and important problems affecting people's quality of life and creating puzzles for the General Practitioners they consult. Little is known about what actions people undertake to deal with fatigue, and even less about their success. As revealed by multivariate analyses health-related action patterns can classify people as being particularly successful or unsuccessful in dealing with their complaints of chronic fatigue. This study suggests that a few actions applied in combination and in a concentrated manner constitute the basis for a successful action pattern. The number, type and predictive power of the relevant actions vary depending on the persons in question: having chronic diseases or not and being under 44 or over 44 years old.

Early HCV RNA values after interferon predict response

The aim of this study is to determine in patients infected with hepatitis C virus (HCV) whether early HCV RNA measurements at 48 hr following standard doses of interferon-alpha (IFN-alpha) (3 million IU) would predict response during six months of therapy. Twenty-three patients with HCV were treated with IFN-alpha 3 million IU three times a week and HCV RNA levels were quantified by branched-chain (b-)DNA analysis at baseline and 24 and 48 hr following IFN-alpha and at one, three, and six months. Mean baseline HCV RNA levels significantly declined from 6.0 +/- 1.6 Meq/ml at baseline to 2.4 +/- 0.7 Meq/ml 24 hr after IFN-alpha. However, HCV RNA values increased to 4.3 +/- 1.1 Meq/ml by 48 hr. Mean HCV RNA values at one and six months were not significantly lower than 48-hr values. In six patients in whom HCV RNA was negative by bDNA at 48 hr, three were negative by polymerase chain reaction at six months. Of the 17 patients who were positive by bDNA at 48 hr, all were positive at one and three months; and in the nine of nine who continued therapy for six months, there was no further decrease in HCV RNA levels. In patients receiving standard doses of IFN-alpha (3 million IU), serum RNA values 48 hr after the first injection predict long-term response.

Association of obesity, gender, age and occupation with carpal tunnel syndrome

BACKGROUND

The present study determines the association of obesity, gender, age and occupation in patients with carpal tunnel syndrome (CTS) in a New Zealand population.

METHODS

Analysis of questionnaires and clinical review of patients who had undergone surgical decompression of the median nerve in the carpal tunnel.

RESULTS

The age and gender distribution of 655 hands (512 patients) that had undergone carpal tunnel release (CTR) were compared with the age and gender distribution of the New Zealand population. The results indicate that the 3-year-period prevalence of CTS in females is more than double that in males. Proportionally there were more patients over age 55 than in the general population. The findings also indicate that, proportionally, six times the number of females who worked in moderate manual work underwent CTR compared with the general female population and proportionally twice the number of males who worked in heavy office/clerical work underwent CTR compared with the general male population. It was also found that CTR patients are twice as likely to be overweight (body mass index [BMI] > 25) than the general population and female patients are twice as likely to be obese (BMI > 30) than the general population.

CONCLUSIONS

Carpal tunnel syndrome is more than twice as common in females as it is in males, and patients aged more than 55 years are more likely to suffer from CTS. Females with CTS are more likely to work in moderate manual work and males with CTS are more likely to work in heavy office/clerical work. Obesity and CTS are related statistically.

Results of open carpal tunnel release: a comprehensive, retrospective study of 188 hands

BACKGROUND

Many recent reports of the results of decompression of the median nerve in the carpal tunnel have concentrated on only one aspect of recovery (numbness, grip etc.), and there are no reports of a comprehensive study of outcome. The aim of the present study was to review comprehensively the results of the direct visualization method of decompression of the carpal tunnel and to compare them with the published results of endoscopic release.

METHODS

Patients' perceptions of the severity of pain, numbness and paraesthesiae due to carpal tunnel syndrome (CTS), before and after open carpal tunnel release (CTR) in 188 hands were reviewed retrospectively at a minimum time of follow-up of 18 months. Motor and sensory testing, provocation testing and measurement of scar tenderness in 135 hands were performed at a clinical review.

RESULTS

Subjective results showed that 70% experienced a reduction in the severity of pain after CTR, 78% of hands experienced a reduction in the severity of paraesthesiae and 77% experienced a reduction in the severity of numbness. A total of 49% had improvements in all three symptoms after CTR. At the clinical review, sensory testing revealed that 59% of hands had normal or slightly diminished light touch, 35% had normal static two-point discrimination and 61% had normal dynamic two-point discrimination. Results for Tinel's test, Phalen's test and pressure provocation testing were positive in 10% of hands. There was no scar tenderness in 38%, no persisting thenar atrophy in 90%. Normal grip strength was found in 93% and 91% had normal pinch strength.

CONCLUSIONS

It was concluded that open carpal tunnel release remains a safe and reliable treatment for carpal tunnel syndrome. The very low incidence of serious complications from the open technique of CTR, when compared with endoscopic CTR as published by different authors in the literature, and the comparable clinical results, appears to make the open technique a safer and preferable option. However, a properly controlled trial of both techniques is necessary to compare them.

Diagnosis and management of fulminant hepatic failure

Fulminant hepatic failure is defined as the development of hepatic encephalopathy within 8 weeks of the onset of illness. While there are many causes of FHF, viral hepatitis, particularly hepatitis B, remains the most common etiology. Several drugs and toxins can also lead to FHF, most notably acetaminophen. Even with improvements in ICU care, mortality remains very high for these patients. Conservative management focuses on invasive monitoring and the prevention and treatment of complications like cerebral edema, infection, renal failure, and coagulopathy. Only orthotopic liver transplantation has reduced mortality from 80% to 30% to 50%. Therefore, the goals of management and treatment now include determining which patients are appropriate for liver transplant and finding a donor in a timely fashion.

Changes in the concentrations of tau and other structural proteins in the brains of aged mice

To test whether aging is associated with alterations in the balance of cytoskeletal constituents, the relative concentrations of tau isoforms and seven other structural proteins were compared in the brains of 3-25-month-old mice. A tau species of approx. 63 kDa was substantially increased in the older animals while the levels of ankyrin, talin, spectrin, and actin were differentially decreased. The decrement in ankyrin was evident at earlier ages than that for spectrin. These results suggest that the make-up of the neuronal cytoskeleton changes with age.

[Lactation and weaning patterns in Mexico. 1986 National Health Survey]

In the process of nutrition, breastfeeding is fundamentally important, due to the nutritional and immunological value of the mother's milk. Within its beneficial effects, it is found that it improves weight and size in children. Another stage in the child's feeding that should be considered during the first year of life is the weaning that complements, at certain age of the breastfeeder, the nutrition given by breastmilk. The decrease or abandonment of breastfeeding is alarming in the developing countries, where this natural product is more available, economical and nutritious. There is evidence that within the health institutions, artificial feeding is encouraged. The National Health Survey collected basic information on sociodemographic variables risk factors, demand and use of health services. It also included questions on breastfeeding and weaning for the population under one year of age. It was found that 19.9 percent was never breastfed. Another important fact is that 42.4 percent of children received breastmilk for just three months or less. This view suggests that breastfeeding in our country is changing, due to various factors, among which we can mention the differences in life styles, education and economical development among states. The results of this study show interesting data that oblige us to consider more detailed and specific analyses in the future.