Differential influence of first- vs. third-person visual perspectives on segmentation and memory of complex dynamic events.

Until now, most studies investigating the relationship between event segmentation and memory have used videos filmed from a third-person perspective, although people experience their lives from a first-person perspective. The present study aimed to determine whether visual perspective impacts events segmentation and further recall. Fifty-seven participants were recruited and assigned to either first- (1PP) or third-person perspective (3PP) condition, before segmenting videos of daily life activities. Our results showed that the although the number of event boundaries was higher in the 3PP condition than in the 1PP, no differences were observed for event segmentation qualitative abilities and organization. Memory of temporal order was better for events encoded in the 3PP than in the 1PP, while memory content was similar in both conditions. Higher event segmentation rates were correlated with a better recall of small actions and temporal order.

Moral distress and psychological status among healthcare workers in a newly established paediatric intensive care unit.

INTRODUCTION: Healthcare workers in intensive care units often experience moral distress, depression, and stress-related symptoms. These conditions can lower staff retention and influence the quality of patient care. This study aimed to evaluate the prevalence of moral distress and psychological status among healthcare workers in a newly established paediatric intensive care unit (PICU) in Hong Kong. METHODS: A cross-sectional questionnaire survey was conducted in the PICU of the Hong Kong Children's Hospital; healthcare workers (doctors, nurses and allied health professionals) were invited to participate. The Revised Moral Distress Scale (MDS-R) Paediatric Version and Depression Anxiety and Stress Scale-21 items were used to assess moral distress and psychological status, respectively. Demographic characteristics were examined in relation to moral distress, depression, anxiety, and stress scores to identify risk factors for poor psychological outcomes. Correlations of moral distress with depression, anxiety, and stress were examined. RESULTS: Forty-six healthcare workers completed the survey. The overall median MDS-R moral distress score was 71. Nurses had a significantly higher median moral distress score, compared with doctors and allied health professionals (102 vs 47 vs 20). Nurses also had the highest median anxiety and stress scores (11 and 20, respectively). Moral distress scores were correlated with depression (r=0.445; P=0.002) and anxiety scores (r=0.417; P<0.05). Healthcare workers intending to quit their jobs had significantly higher moral distress scores (P<0.05). CONCLUSION: Among PICU healthcare workers, nurses had the highest level of moral distress. Moral distress was associated with greater depression, anxiety, and intention to quit. Healthcare workers need support and a sustainable working environment to cope with moral distress.

Effect of sitting position on equal-dose spinal anaesthetic for caesarean section and post-partum tubal ligation.

BACKGROUND: We studied the hypothesis that an equal spinal anaesthetic dose administered in the sitting position to patients undergoing post-partum tubal ligation (PPTL) and caesarean section (CS) would yield similar sensory block characteristics and analgesic efficacy. METHODS: This prospective, non-randomised trial recruited 20 women undergoing PPTL within 48 h of vaginal delivery and 20 undergoing CS. Spinal anaesthesia comprising intrathecal hyperbaric bupivacaine 12 mg and morphine 100 µg was administered at L3/4 with patients sitting. Our primary end point was the maximal dermatomal sensory block (to cold). RESULTS: Baseline demographics were comparable, but PPTL patients had greater parity, with mean ± standard deviation 17.54 ± 11.2 h from delivery to spinal anaesthesia, and shorter duration of surgery, 17.54 ± 11.2 vs. 40.3 ± 15.5 min. Similar maximal sensory blocks (to cold) were achieved in group PPTL vs. CS, T4 (T1-T5) vs. T3 (T1-T5), P = 0.104, in comparable times, 8.6 ± 2.6 vs. 7.6 ± 3.0 min, P = 0.267. PPTL patients had significantly faster two-segment block regression (70.7 ± 23.5 vs. 97.6 ± 23.9 min, P = 0.001) and to T10 (120.8 ± 35.6 vs. 145.1 ± 24.3 min, P = 0.016), with less hypotension (25% vs. 65%, P = 0.025) and phenylephrine (20.0 ± 60.6 µg vs. 120.0 ± 119.6 µg, P = 0.005). CONCLUSION: The same dose of hyperbaric bupivacaine 12 mg and morphine 100 µg administered in the sitting position to both PPTL and CS parturients yielded similar maximal sensory blocks, but PPTL exhibited faster block regression and less hypotension/vasopressor requirement.

Gene transfer and expression of human phenylalanine hydroxylase.

Phenylketonuria (PKU) is caused by a genetic deficiency of the enzyme phenylalanine hydroxylase (PAH). A full-length complementary DNA clone of human PAH was inserted into a eukaryotic expression vector and transferred into mouse NIH3T3 cells which do not normally express PAH. The transformed mouse cells expressed PAH messenger RNA, immunoreactive protein, and enzymatic activity that are characteristic of the normal human liver products, demonstrating that a single gene contains all of the necessary genetic information to code for functional PAH. These results support the use of the human PAH probe in prenatal diagnosis and detection of carriers, to provide new opportunities for the biochemical characterization of normal and mutant enzymes, and in the investigation of alternative genetic therapies for PKU.

Laparoscopic radical prostatectomy: single centre experience after 5 years.

OBJECTIVE: To summarise our experience of laparoscopic radical prostatectomy in a single centre in Hong Kong over 5 years. DESIGN: Retrospective study. SETTING: Urology Division, Department of Surgery, Tuen Mun Hospital, Hong Kong. PATIENTS: A total of 87 patients who underwent laparoscopic radical prostatectomy from March 2002 to May 2007. MAIN OUTCOME MEASURES: Peri-operative data and follow-up information. RESULTS: The operative procedure used entailed Montsouris technique and its modifications, including the latest method involving the extraperitoneal descending technique. In all, 87 patients underwent the operation; in two, the procedure was converted to open surgery. Peri-operative parameters which showed improvement included: operating time, blood loss, resort to blood transfusions, and the complication rate. There was no operation-related mortality. In organ-confined disease, a clear surgical margin was achieved in 93% of the patients, but in those whose disease was not organ-confined, the positive margin rate was 87%. Among patients with organ-confined disease, 13% had evidence of biochemical recurrence. Hormonal therapy was started in five patients, none of whom died during the follow-up period (mean, 24 months). Continence recovered in 69% of the patients by 6 months and in 92% by 12 months post-surgery. Assessment of erectile function before and after the surgery was problematic and estimated to be 20% among patients having the nerve-sparing procedure performed. CONCLUSION: Although Hong Kong has a relatively low incidence for prostate cancer, it was possible to develop laparoscopic radical prostatectomy with acceptable early results. Further follow-up is warranted before formulating definitive conclusions about this procedure.

'Street ketamine'-associated bladder dysfunction: a report of ten cases.

Ten young ketamine abusers presented with lower urinary tract symptoms to two regional hospitals in Hong Kong. Investigations demonstrated contracted bladders and other urinary tract abnormalities. These types of findings have never been reported before in ketamine abusers. The possible aetiology is also discussed.

Characterization of multiple prohormone convertase PC1/3 transcripts in porcine ovary.

Overlapping cDNAs encoding porcine prohormone convertase, PC1/3, have been isolated from a pregnant sow ovary cDNA library using a mouse PC1/3 cDNA as a probe. Nucleotide sequence analysis of these cDNAs predicts a PC1/3 precursor protein of 753 amino acid residues, which shares an overall sequence homology of 96, 92, and 92% with the human, rat, and mouse counterparts, respectively. Furthermore, five different polyadenylation sites have been observed. The utilization of these polyadenylation sites results in a length difference of 40-440 bp in the 3' untranslated regions of the transcripts.

Identification of a point mutation in the human insulin gene giving rise to a structurally abnormal insulin (insulin Chicago).

Both insulin gene alleles of a diabetic patient with a mutant insulin were cloned in a lambda vector and their nucleotide sequences were determined. Nucleotide sequence analysis revealed, in one allele, a C (cytidylate) to G (guanylate) transversion in the codon for phenylalanine at position 25 of the insulin B-chain. This point mutation leads to the substitution of a leucine for phenylalanine accompanied by the loss of a restriction endonuclease Mboll recognition site and the creation of a new Rsal cleavage site at this position.

Transplantable rat choriocarcinoma cells express placental lactogen: identification of placental lactogen-I immunoreactive protein and messenger ribonucleic acid.

The purpose of this investigation was to evaluate the abilities of a transplantable rat choriocarcinoma (Rcho) to produce placental PRLs. The Rcho tumor was analyzed biochemically and histologically for the expression of placental PRLs. Expression of placental PRL mRNAs was determined by Northern blot and in situ hybridization analyses. Expression of placental PRL proteins was determined by Western blot and immunocytochemical analyses. Histologically, Rcho tumors were characterized by the appearance of giant cell surrounding hemorrhagic regions. Female rats bearing the Rcho tumor beneath their kidney capsule showed extensive mammary gland development. The Rcho tumors expressed placental lactogen-I (PL-I) mRNA and protein, but there was no evidence of placental lactogen-II (PL-II), PRL-like protein-A (PLP-A), or PRL-like protein-B (PLP-B). Rcho PL-I mRNA and proteins migrated as a 1-kilobase species and a 36- to 40-kDa species similar to those expressed by normal rat trophoblast tissues. The cell type responsible for Rcho PL-I production was the giant cell, similar to that observed in normal rat trophoblast tissues. In summary, we have demonstrated the production of PL-I by a transplantable rat choriocarcinoma (Rcho). The Rcho tumor resembles rat trophoblast tissue at early postimplantation stages (days 6-10 of gestation) and may be a useful tool for studying placental PRL expression during trophoblast differentiation.

Differential expression of placental lactogen-II and prolactin-like protein-A in the rat chorioallantoic placenta.

The rat chorioallantoic placenta is comprised of two morphologically distinct regions: the junctional zone and the labyrinth zone. The purpose of this investigation was to determine the relative contributions of trophoblast cells in each of these regions to the expression of placental lactogen-II (PL-II) and PRL-like protein-A (PLP-A) during development, mRNA expression was estimated by Northern blot analysis, whereas, protein expression was estimated by electrophoresis, immunoblotting, and immunocytochemical analyses. The immunochemical analyses used antipeptide antisera directed to amino acids 56-70 of PL-II and amino acids 152-164 of PLP-A. Northern and immunoblotting analyses indicated that both PL-II mRNA and protein expression were maximal in the junctional zone on day 13 of gestation and declined as gestation proceeded. In contrast, PL-II mRNA and protein expression in the labyrinth zone were low on day 13 and increased as gestation advanced. PL-II was specifically localized to giant cells. At midgestation, PL-II-positive giant cells were identified bordering the uterine decidua in the junctional zone and choriovitelline placenta. As gestation advanced. PL-II-positive cells were also localized to the labyrinth zone. Immunoreactivity was restricted to the cytoplasm of PL-II-positive cells. PLP-A mRNA and protein were predominantly expressed in the junctional zone of the chorioallantoic placenta. Expression of PLP-A increased as gestation advanced. PLP-A was specifically localized to giant and spongiotrophoblast cells of the junctional zone. Immunoreactivity was found in both cytoplasmic and nuclear compartments of PLP-A-positive cells. In summary, PL-II expression shifts from the junctional to the labyrinth zone during pregnancy, whereas PLP-A is predominantly expressed in the junctional zone during the latter third of pregnancy. Both hormones are produced by giant cells of the junctional zone, but only PL-II is expressed by choriovitelline and labyrinthine trophoblast cells. PLP-A is also expressed by spongiotrophoblast cells of the junctional zone. These findings provide insights into the process of placental morphogenesis.

Prolactin-like protein-C variant: complementary deoxyribonucleic acid, unique six exon gene structure, and trophoblast cell-specific expression.

The rat placental PRL family consists of proteins structurally related to pituitary PRL. As a consequence of attempting to characterize the gene for one of the members of the family, PRL-like protein-C (PLP-C), we identified a related gene that we have termed PLP-C variant (PLP-Cv). In this study, we present information on the PLP-Cv gene and its pattern of expression. Screening of a rat genomic library with a PLP-C cDNA resulted in the isolation of four phage clones. Nucleotide sequence analysis of the clones revealed a gene, PLP-Cv, closely related but distinct from PLP-C. The PLP-Cv gene possessed a six exon/five intron organization, unique among members of the PRL family, and was localized to chromosome 17 of the rat genome, similar to other PRL family members. A PCR strategy involving primers based on the PLP-Cv gene was used to isolate a placental PLP-Cv cDNA. PLP-Cv showed 90 and 78% sequence identity with PLP-C at nucleotide and amino acid levels, respectively. Expression of PLP-Cv was restricted to the trophoblast lineage and was coordinately activated with PLP-C beginning at day 11 of gestation and continuing until term. Primer extension analysis revealed multiple putative transcription start sites. A 2.1-kilobase pair PLP-Cv promoter-luciferase reporter construct was specifically activated in differentiating rat trophoblast cells but not in other cell types. In conclusion, we have identified a new member of the PRL family possessing considerable homology to PLP-C, a unique gene structure, and displaying a trophoblast-specific pattern of transcriptional activation.

Rcho-1 trophoblast cell placental lactogens: complementary deoxyribonucleic acids, heterologous expression, and biological activities.

In this report, we have investigated placental lactogens (placental lactogen-I, PL-I; PL-I variant, PL-Iv; PL-II) expressed by differentiated Rcho-1 trophoblast cells. A complementary DNA (cDNA) library to differentiated Rcho-1 trophoblast cells was constructed and screened with probes to detect PL-I and PL-II. Sequence analysis of three independent Rcho-1 PL-I cDNAs indicated that they significantly differed from the previously reported PL-I sequence but more closely resembled a related cDNA referred to as PL-I mosaic (PL-Im). Upon further analysis, Rcho-1 PL-I/PL-Im transcripts could be detected in Rcho-1 trophoblast cells and normal developing placental tissue; however, the previously reported PL-I transcript could not be identified from the same sources. Given these results, we examined the original PL-I cDNA by PCR and nucleotide sequence analyses. The sequence differed from the original report and was found to be identical to the Rcho-1 PL-I and PL-Im cDNA clones. Thus, PL-I, Rcho-1 PL-I, and PL-Im are equivalent and should be referred to as PL-I. The PL-I gene was localized to chromosome 17 of the rat genome, similar to other PRL family members. Rcho-1 PL-II cDNAs were identical to the published PL-II sequence. PL-Iv cDNAs were isolated from differentiated Rcho-1 cells via an RT-PCR strategy and found to be identical to previously isolated PL-Iv cDNAs. Rcho-1 PL-I and PL-II cDNAs were subcloned into the pcDNA3 expression vector and recombinant protein produced in HRP-1 cells. Both recombinant Rcho-1 PL-I and PL-II proteins significantly stimulated the proliferation of lactogen-dependent rat Nb2 lymphoma cells and mouse mammary epithelial cells. In summary, we show that the Rcho-1 PL-I corresponds to PL-Im and Rcho-1 PL-Iv and PL-II are identical to their previously described placental counterparts. Additionally, both recombinant Rcho-1 PL-I and PL-II proteins are biologically active.

Relaxin purification from human placental basal plates.

A crude relaxin preparation has been obtained from the basal plate region of electric cesarean section human placentae, as well as normal term placentae. The relaxin isolated has different charge properties by ion exchange chromatography from porcine relaxin, although it is of approximately the same molecular size. The most potent fraction obtained has approximately 0.7% of the immunoactivity of purified porcine relaxin when compared with porcine relaxin in a RIA based on porcine material, suggesting significant amino acid sequence differences between the putative human relaxin and its porcine counterpart.

Expression of alkaline phosphatase in differentiated rat labyrinthine trophoblast tissue.

In this report, we describe the generation of specific antibodies to rat alkaline phosphatase and the temporal and regional characteristics of alkaline phosphatase expression during maturation of the rat chorioallantoic placenta. An antipeptide antiserum was generated to the amino terminal 15 amino acids of rat alkaline phosphatase. The antiserum specifically recognized alkaline phosphatase. Alkaline phosphatase expression was monitored in the junctional and labyrinth zones of the chorioallantoic placenta by Western and Northern blot analyses. Alkaline phosphatase protein and mRNA were present in both the junctional and labyrinth zones on day 13 of gestation. As gestation advanced, alkaline phosphatase mRNA and protein expression decreased below the limits of detection in the junctional zone, while alkaline phosphatase expression increased in the labyrinth zone. Labyrinthine alkaline phosphatase migrated predominantly as a 95-kDa species, whereas rat kidney expressed exclusively the 75-kDa species. Enzymatic deglycosylation of the 75- and 95-kDa alkaline phosphatase species resulted in the generation of a 55-kDa species. In summary, alkaline phosphatase expression is a useful indicator of trophoblast differentiation.

Placental lactogen-I variant utilizes the prolactin receptor signaling pathway.

Placenta lactogen-I variant (PL-Iv) is a member of a family of proteins expressed by the rat placenta with characteristics similar to prolactin (PRL). In this report, we present the molecular cloning, chromosomal localization, and heterologous expression of PL-Iv. Nucleotide sequence analysis of the PL-Iv cDNA clone predicted a precursor protein of 223 amino acids, including a 28-amino acid signal sequence. The PL-Iv gene was localized to chromosome 17 of the rat genome, which also carries other members of the PRL gene family. PL-Iv heterologously expressed in Chinese Hamster ovary (CHO) cells exhibited similar immunoreactive and electrophoretic characteristics with PL-Iv produced by the rat placenta. N-terminal sequencing verified the identity and purity of the recombinant PL-Iv species and the site of cleavage of the signal peptide from the mature secreted PL-Iv species. Recombinant PL-Iv was shown to bind to ovarian and liver PRL receptors, stimulate the proliferation of Nb2 lymphoma cells, and activate Jak2. Each of these actions is consistent with PL-Iv utilizing the PRL receptor signal transduction pathway.

Activation of platelets adhered on amorphous hydrogenated carbon (a-C:H) films synthesized by plasma immersion ion implantation-deposition (PIII-D).

Amorphous carbon films have attracted much attention recently due to their good biocompatibility. Diamond-like carbon (DLC), one form of amorphous carbon that is widely used in many kinds of industries, has been proposed for use in blood contacting medical devices. However, the blood coagulation mechanism on DLC in a biological environment is not well understood. Platelet adhesion and activation are crucial events in the interactions between blood and the materials as they influence the subsequent formation of thrombus. In this work, the behavior of platelets adhered onto hydrogenated amorphous carbon films (a-C:H) is investigated. Hydrogenated amorphous carbon films with different hydrogen contents, structures, and chemical bonds were fabricated at room temperature using plasma immersion ion implantation-deposition (PIII-D). The wettability of the films was investigated by contact angle measurements using several common liquids. Platelet adhesion experiments were conducted to examine the interaction of blood with the films in vitro and the activation of adherent platelets. The results show that the behavior of the platelets adhered on the a-C:H films is influenced by their structure and chemical bond, and it appears that protein interaction plays a key role in the activation of the adherent platelets.

Molecular cloning and sequence analysis of the cDNA encoding porcine acrosin inhibitor.

A full-length cDNA encoding the porcine acrosin inhibitor has been isolated from a boar seminal vesicle cDNA library. Nucleotide sequence analysis of the 667-bp cDNA predicts a precursor protein of 97 amino acid residues, which includes a 26-residue signal peptide and a 71-residue secreted protein. The predicted amino acid sequence of the mature protein agrees completely with that of the sperm-associated acrosin inhibitor determined by conventional amino acid sequence analysis. However, the asparagine/aspartic acid and glutamine/glutamic acid substitutions, as reported in the seminal plasma counterpart, have not been observed. Southern blot analysis shows only a single hybridizing band with three different restriction endonucleases, suggesting the presence of a single copy of the acrosin inhibitor gene in the porcine genome.

Molecular cloning, expression, localization, and gene organization of PTX1, a human nuclear protein that is downregulated in prostate cancer.

A cDNA, designated PTX1, has been isolated by subtractive hybridization on the basis that it is expressed in normal prostate but not in prostate carcinoma. The full-length cDNA was subsequently established by 5' and 3' RACE. Nucleotide sequence analysis of the 5'- and 3'-RACE clones yielded a composite cDNA of 1327 bp, which predicted a protein of 377 amino acid residues with a putative nuclear import signal (RRLNRKK) at its N terminus. The PTX1 gene was localized to human chromosome 12 and was found to be ubiquitously expressed. A segment of the cDNA was expressed in E. coli to produce a fragment of the PTX1 protein for the generation of specific antibodies. The resulting antibodies detected a 73-kDa protein in both nuclear and cytoplasmic extracts of prostate, although the level in the cytoplasmic extract was much lower. Using immunohistochemical analysis, the PTX1 protein was localized mainly in the nuclei of glandular epithelia of normal prostate. The nuclear staining was greatly reduced in prostate carcinoma. The gene organization of PTX1 was established by comparing the cDNA sequence with the published human genomic sequence.

Molecular cloning and sequence analysis of two porcine seminal proteins, PSP-I and PSP-II: new members of the spermadhesin family.

Two full-length cDNAs encoding porcine seminal proteins, PSP-I and PSP-II, have been isolated from a porcine seminal vesicle cDNA library. Nucleotide sequence analysis of the 706-bp PSP-I cDNA predicts a precursor protein of 133 amino acid residues, which includes a 21-residue signal peptide and a 112-residue secreted protein. On the other hand, the complete sequence of the 686-bp PSP-II cDNA reveals a coding sequence for a 21-residue signal peptide and a 116-residue secreted protein. The predicted amino acid sequences agree very well with those determined by conventional amino acid sequence analysis. Alignment of the two cDNA sequences shows an overall 66% sequence homology throughout their entire length. However, the sequence homology is much higher in the 3' untranslated region (72%) than in the coding region (61%). This suggests that these two genes evolved by duplication and divergence from a common ancestral gene. They share about 50% amino acid sequence homology and a similar overall structure with three members of the spermadhesin family.

Recombinant porcine prorelaxin produced in Chinese hamster ovary cells is biologically active.

Although prorelaxin has a similar structure as proinsulin, the posttranslational processing of prorelaxin seems to be quite different from that of proinsulin. There are no pairs of basic residues flanking the relaxin moiety in most prorelaxins studied so far. Instead, the prorelaxins of many species contains a tetrabasic sequence (Arg-Lys-Lys-Arg) between the connecting peptide and the A-chain. This is the recognition sequence of furin. In order to study this possible processing by furin, we express the recombinant porcine prorelaxin in Chinese hamster ovary cells. The expected 19 kDa recombinant porcine prorelaxin was found to be constitutively secreted into the medium at a level of approximately 250 ng/ml. No conversion of the 19 kDa prorelaxin into the 6 kDa relaxin was observed. Unlike most prohormones which are biologically inactive, the recombinant prorelaxin was found to be biologically active in an in vitro bioassay.