Hedgehog signaling in germ cell migration

The primitive gonad of the Drosophila embryo is formed from two cell types, the somatic gonad precursor cells (SGPs) and the germ cells, which originate at distant sites. To reach the SGPs the germ cells must undergo a complex series of cell movements. While there is evidence that attractive and repulsive signals guide germ cell migration through the embryo, the molecular identity of these instructive molecules has remained elusive. Here, we present evidence suggesting that hedgehog (hh) may serve as such an attractive guidance cue. Misexpression of hh in the soma induces germ cells to migrate to inappropriate locations. Conversely, cell-autonomous components of the hh pathway appear to be required in the germline for proper germ cell migration.

Molecular cloning and nuclear localization of a histone deacetylase homologue in Plasmodium falciparum

Reversible acetylation of core histones plays an important role in transcriptional regulation, cell cycle progression and developmental events. The acetylation state of histones is controlled by a dynamic equilibrium between activities of histone acetylase and deacetylase enzymes. Histone deacetylase (HDAC) was recently suggested to be the target of a fungus-derived antiprotozoal agent exhibiting structural similarity to known HDAC inhibitors. We have initiated a study of HDAC of human malaria parasite, Plasmodium falciparum, to evaluate its potential as the target for novel antimalarials and its role in parasite development. We have isolated HDAC1 gene from the P. falciparum genomic and cDNA libraries. The nucleotide sequence contains no intervening sequence and its open reading frame (ORF) codes for a protein of 449 amino acid residues. We have named the protein, PfHDAC1, as the sequence shows significant homology to yeast, human and other eukaryotic HDACs. Northern blot analysis of the total RNA from different asexual and sexual stages of the parasite reveals the presence of single mRNA transcript, which is predominantly expressed in mature asexual blood stages and in gametocytes. Antiserum raised against a carboxyl terminal peptide immunoprecipitated an in vitro translated P. falciparum HDAC gene product and recognized an approximately 50 kDa protein in the Triton X-100 insoluble fraction of parasites. Immunoelectron microscopy analysis showed majority of the protein localized in the nucleus of P. falciparum. To our knowledge, this is the first HDAC gene isolated from the malaria parasite.

Adenosine modulation of neurotransmission in penile erection

1. Adenosine inhibited the noradrenaline-induced contraction of rabbit corpus cavernosum in a dose-dependent manner. The effect of adenosine was greater in intact corpus cavernosa than in endothelium-denuded preparations. This finding indicates that the relaxing effect of adenosine is partially endothelium-dependent and involved in the release of endothelium-derived relaxing factors. 2. Adenosine and its analogues relaxed the noradrenaline-induced contractile response as well as inhibited the transmural nerve induced contraction with the potency order: NECA > R-PIA > adenosine. These data indicate that adenosine can modulate both the non-adrenergic non-cholinergic and adrenergic neurotransmission. DMPX, an adenosine antagonist selective for the A2 receptors, abolished the electrically elicited relaxation. However, CGS 21680, selective for A2a receptor, had no effect on relaxation. Therefore, adenosine receptors involved in the modulation of neurotransmission in rabbit corpus cavernosum appear to be A2b subtype. 3. Adenosine also induced an increase in human cavernosal arterial velocity and resistive index measured by colour duplex sonography. The combination of adenosine and 10 micrograms prostaglandin E1 was more effective in resistive index and erection grade than 20 micrograms prostaglandin E1 alone. Our results suggest that adenosine seems to be an important neuromodulator for penile erection and can be an effective and alternative combination in the treatment of impotence.

Pentoxifylline stimulates human sperm motility both in vitro and after oral therapy

Pentoxifylline is a haemorrheologic agent often used in the treatment of peripheral vascular disorders. In this study, we measured sperm motility with a trans-membrane migration method and investigated the effect of this drug in the treatment of male infertility. We found that pentoxifylline increased motility of ejaculated spermatozoa in vitro from both normal and asthenozoospermic samples. After giving pentoxifylline to patients with asthenozoospermia for 3 months, sperm motility significantly increased, but sperm concentration did not increase. From the above results, it can be concluded that pentoxifylline is a useful drug in the treatment of normogonadotropic asthenozoospermia.

Cancer beliefs in ethnic minority populations: a review and meta-synthesis of qualitative studies

People from ethnic minorities often experience poorer cancer outcomes, possibly due to later presentation to healthcare and later diagnosis. We aimed to identify common cancer beliefs in minority populations in developed countries, which can affect symptom appraisal and help seeking for symptomatic cancer. Our systematic review found 15 relevant qualitative studies, located in the United Kingdom (six), United States (five), Australia (two) and Canada (two) of African, African-American, Asian, Arabic, Hispanic and Latino minority groups. We conducted a meta-synthesis that found specific emotional reactions to cancer, knowledge and beliefs and interactions with healthcare services as contributing factors in help seeking for a cancer diagnosis. These findings may be useful to inform the development of interventions to facilitate cancer diagnosis in minority populations.

Hysteroscopic resection of vaginal septum in an adolescent virgin with obstructed hemivagina

This article reports on one patient with a double uterus, unilateral vaginal obstruction, with hemi-haematocolpos and ipsilateral renal agenesis. Early accurate diagnosis followed by the excision of the obstructing vaginal septum offers complete relief of symptoms, while preserving reproductive capacity. Unlike conventional excision of vaginal septum, we used resectoscope excision with cutting electrode under continuous pure distilled water irrigation. The postoperative course was uneventful, and haematocolpos and severe dysmenorrhoea disappeared. The resected vaginal area revealed re-epithelialization by hysteroscope follow-up one year after resection. With advancements in resectoscopic operation, evaluation and treatment of vaginal disorders in babies and virgins is very feasible.

M(1)-like muscarinic acetylcholine receptors regulate fast-spiking interneuron excitability in rat dentate gyrus

Cholinergic transmission through muscarinic acetylcholine receptors (mAChRs) plays a key role in cortical oscillations. Although fast-spiking (FS), parvalbumin-expressing basket cells (BCs) are proposed to be the cellular substrates of gamma oscillations, previous studies reported that FS nonpyramidal cells in neocortical areas are unresponsive to cholinergic modulation. Dentate gyrus (DG) is an independent gamma oscillator in the hippocampal formation. However, in contrast to other cortical regions, the direct impact of mAChR activation on FS BC excitability in this area has not been investigated. Here, we show that bath-applied muscarine or carbachol, two mAChR agonists, depolarize DG BCs in the acute brain slices, leading to action potential firing in the theta-gamma bands in the presence of blockers of ionotropic glutamate and gamma-aminobutyric acid type A receptors at physiological temperatures. The depolarizing action persists in the presence of tetrodotoxin, a voltage-gated Na(+) channel blocker. In voltage-clamp recordings, muscarine markedly reduces background K(+) currents. These effects are mimicked by oxotremorine methiodide, an mAChR-specific agonist, and largely reversed by atropine, a non-selective mAChR antagonist, or pirenzepine, an M(1) receptor antagonist, but not by gallamine, an M(2/4) receptor antagonist. Interestingly, in contrast to M(1)-receptor-mediated depolarization, M(2) receptor activation by the specific agonist arecaidine but-2-ynyl ester tosylate down-regulates GABA release at BC axons-the effect is occluded by gallamine, an M(2) receptor antagonist. Overall, muscarinic activation results in a net increase in phasic inhibitory output to the target cells. Thus, cholinergic activation through M(1)-like receptor enhances BC activity and promotes the generation of nested theta and gamma rhythms, thereby enhancing hippocampal function and associated performance.

Adenosine stimulates human sperm motility via A2 receptors

The effects of adenosine and its analogues on human sperm motility were studied using a transmembrane migration method. Specific binding sites for adenosine in human sperm were also investigated. Adenosine and 5'-N-ethylcarboxamidoadenosine (NECA) stimulated human sperm motility with similar efficacies and the maximal amplitudes of motility increases were both about 70%. 3,7-Dimethyl-1-propargylxanthine (DMPX), a potent A2 antagonist, competitively antagonized NECA-induced motility stimulation. Successively higher concentrations of DMPX shifted the dose-response curve of NECA to the right in a nearly parallel fashion. Dipyridamole, an inhibitor of adenosine uptake, does not reduce the ability of adenosine to stimulate human sperm motility. In radioligand-binding studies, adenosine A1 selective analogues, cyclopentyl-1,3-dipropylxanthine and 1-methyl-2-phenylethyl adenosine, have little competitive effect on [3H]NECA binding in human sperm membrane. These results provide evidence that adenosine enhances human sperm motility via adenosine A2 receptors on the surface of sperm membranes.

Study of the changes in collagen of the tunica albuginea in venogenic impotence and Peyronie's disease

We identified the collagen type and content of the tunica albuginea in Peyronie's disease and venogenic impotence compared with the tunica albuginea from the donor of the renal transplant and patients with penile injury. Type III collagen was detected obviously in Peyronie's plaque and was also present in venogenic impotence. It can be hardly found in normal controls. The ratios of type III to type I collagen were significantly higher in Peyronie's plaque while there was a moderate increase in venogenic impotence. The scarcity of type V collagen was noted in human tunica albuginea. The decreased percentage of glycine and alanine in Peyronie's disease and venogenic impotence implied the abnormal composition of collagen or presence of noncollagen protein. The results suggest the biochemical aberration of the tunica albuginea might interfere with the normal function of the penile drainage system.

Pilot study of transurethral needle ablation (TUNA) in treatment of nonbacterial prostatitis

Transurethral needle ablation (TUNA) was performed on seven patients with chronic nonbacterial prostatitis who failed to respond to conventional treatments administered for more than half a year. The TUNA procedure heated the prostate to a temperature ranging from 90 degrees to 100 degrees C while the urethral temperature was maintained below 43 degrees C by a protective sheath and irrigation. After treatment, four patients showed complete resolution of symptoms and three a partial improvement. All patients had a decrease in the leukocyte count in expressed prostatic secretions (EPS) 1 month after treatment. Recurrence of abnormal inflammatory cells in the EPS was noted in two patients at 3 months after treatment. The subjective improvement has been maintained during the subsequent follow-up. From these results, TUNA is considered to be an effective, safe, and easy treatment for most patients with nonbacterial prostatitis.

Outbreak of hepatitis A virus infection in Taiwan, June 2015 to September 2017

The Taiwan Centers for Disease Control (CDC) were notified of increasing acute hepatitis A (AHA) in June 2015. Serum and/or stool from AHA patients and sewage samples were tested for hepatitis A virus (HAV). We defined outbreak cases as AHA patients with illness onset after June 2015 and with an HAV sequence less than 0.5% different from that of the TA-15 outbreak strain. We analysed characteristics and food exposures between outbreak and non-outbreak cases between January 2014 (start of enhanced surveillance) and February 2016. From June 2015 to September 2017, there were 1,563 AHA patients with a median age of 31 years (interquartile range (IQR): 26-38); the male-to-female ratio was 8.8 and 585 (37%) had human immunodeficiency virus (HIV) infection. TA-15 was detected in 82% (852/1,033) of AHA patients, and 14% (74/540) of sewage samples tested since July 2015. Infection with the TA-15 strain was associated with having HIV, sexually transmitted infections (STI), recent oral-anal sex and men who have sex with men (MSM). The Taiwan CDC implemented an HAV vaccine campaign starting from October 2016 where 62% (15,487/24,879) of people at risk were vaccinated against HAV. We recommend HAV vaccination for at-risk populations and continuous surveillance to monitor control measures.

Colour duplex sonography in the assessment of impotence

We present our experience with colour duplex sonography (Acuson 128) in the assessment of 83 impotent men. Cavernosal artery measurements were taken before and after the intracorporeal injection of papaverine. The peak velocities following papaverine injection correlated well with the degree of clinical response. Percentage diameter change corresponded with some groups of clinical erection grade, although it was not as good a discriminator as peak velocity. Twelve patients with 24 cavernosal arteries were also examined using pharmacological selective arteriography. Correlation between duplex sonography and arteriography showed an accuracy of 87.5%, specificity of 100.0% and sensitivity of 82.4%. All patients with a clinically good response following papaverine injection had peak bilateral cavernosal artery velocities greater than or equal to 25 cm/s. Amongst the remaining suboptimal responders, 18 also had this finding. Fifteen of these underwent pharmacological cavernosography and 14 exhibited venous leakage. Duplex sonography is a valuable and non-invasive tool in the assessment of impotence and can provide valuable information in deciding the course of further evaluation and treatment. The procedure was always completed more quickly with the guidance of colour Doppler.

Transitional cell carcinoma of the renal pelvis and ureter in Taiwan. DNA analysis by flow cytometry

BACKGROUND

The incidence of upper urinary tract tumors is relatively high in southern Taiwan. DNA analysis by means of flow cytometry is not well investigated with regard to tumors of the upper urinary tract and the differences in DNA ploidy between transitional cell carcinomas in endemic and nonendemic areas.

METHODS

A retrospective nuclear DNA ploidy analysis by flow cytometry comprised 41 formaldehyde solution-fixed, paraffin-embedded tissue specimens of transitional cell carcinoma of the renal pelvis and ureter. The preparation of nuclear suspensions from paraffin-embedded tissue blocks and staining were modified by means of the techniques of Hedley and Vindeløv.

RESULTS

There was no statistical correlation between DNA ploidy, histologic grade, and pathologic stage, however, 82% of the DNA nondiploid tumors showed tumor progression. In contrast, only 46% of the DNA diploid tumors revealed tumor progression. Among Grade 2 tumors, 85% of the DNA nondiploid tumors showed postoperative tumor progression, whereas only 31% of the DNA diploid tumors showed tumor progression. Seventy-nine percent of the nondiploid patterns were present in patients native to the Pa Chang Valley, where the so-called "blackfoot disease" and urothelium tumor are endemic, whereas only 22% appeared in patients living in other areas.

CONCLUSIONS

DNA flow cytometry can identify a group of patients with poor outcome unpredictable by pathologic examination, and is an important tool in research into the pathogenesis of cancer.

Vector-mediated expression of erythropoietin improves functional outcome after cervical spinal cord contusion injury

We evaluated the therapeutic effect of erythropoietin (EPO) delivered by direct injection of a nonreplicating herpes simplex virus (HSV)-based vector coding for EPO (vEPO) in a model of cervical hemicord contusion at C7. At 1 h after spinal cord injury (SCI), either vEPO or control vector carrying a reporter gene (vC) was injected into the cord above and below the lesion. Animals injected with vEPO showed a statistically significant improvement in the ipsilateral forelimb function, as measured by open-field evaluation of motor performance, forelimb reaching in the cylinder test and misplacement in grid walk. This correlated with preservation of gray matter in the area of the lesion. There was also mild but significant improvement of hindlimb motor function measured by Basso-Beattie-Bresnahan score and computerized gait analysis in vEPO compared with control vector-injected animals. Microtubule-associated protein tau, phosphorylated and nonphosphorylated neurofilament protein and the synaptic proteins synaptophysin and PSD-95 were all significantly increased in the spinal cord of vEPO-treated animals compared with control vector-injected animals. These data suggest that gene transfer of EPO after cervical SCI by minimizing the injury size and enhancing tissue sparing preserves large-caliber axons and promotes synaptogenesis.

Effects of pentoxifylline in the hamster zona-free oocyte spermatozoa penetration assay and on spermatozoa transmembrane migration motility

The effects of pentoxifylline on capacitation, acrosome reaction and motility of spermatozoa in vitro were evaluated by the hamster zona-free oocyte penetration assay and the transmembrane migration method, respectively. The improvement in penetration capacity by the addition of pentoxifylline 40 min before coincubation had a trend toward statistical significance (0.05 less than less than 0.1) in normal fertile men and had statistical significance (p less than 0.05) in asthenospermic patients. There was no improvement by the addition of pentoxifylline 16 h before coincubation. Pentoxifylline significantly increased sperm motility in both normal (p less than 0.001) and asthenospermic patients (p less than 0.05) in the transmembrane migration method. This study showed that pentoxifylline could be used as a stimulant of in vitro sperm motility in male infertility.

The hypotensive action of 3-deaza-adenosine

The effects of 3-deaza-adenosine on the cardiovascular system was investigated in normotensive (WKY) and spontaneously hypertensive rate (SHR). This compound (50 mg/kg i.p. 2X) significantly lowers blood pressure in both groups of animals, an effect which lasts for up to 2 h. The hypotensive effect is not affected by ganglion blockade, and appears to be due in part to a direct effect on blood vessels. While the response is similar to that seem with adenosine, it is more long-lasting. The results of this study suggest a potential role for this compound or analogues of its as possible antihypertensive agents.

Tracking the assembly pathway of human immunodeficiency virus type 1 Gag deletion mutants by immunogold labeling

The Pr55gag gene product of human immunodeficiency virus type 1 (HIV-1) is sufficient to direct the formation of retrovirus-like particles (RVLPs). Recent biochemical evidence has indicated the presence of Gag intermediates in the cytoplasm; however, the Gag assembly process into RVLPs remains incompletely defined. The authors present here the subcellular localization of Gag mutant proteins in BSC40 and Jurkat cells by immunoelectron microscopy (IEM). The full Gag/Pol and Gag precursors, a C-terminal deletion mutant lacking a portion of nucleocapsid (NC), and all p6Gag gave rise to similar levels of RVLPs at the cell surface. A C-terminal deletion of all NC and p6Gag abrogated particle formation, whereas p24 was found in patches at the cell surface. Deletion of matrix (MA) sequences from Gag resulted in intracellular particles, and myristylation was not required for particle formation in the context of the MA deletion. Matrix expression was enhanced with Gag/Pol or Env coexpression as determined by semiquantitative IEM. p24 protein was targeted at vacuolar and mitochondrial membranes, but not at Golgi cisternae. In addition, aggregations of Gag intermediates and RVLPs in the cytoplasm, rough endoplasmic reticulum, cisternae, and mitochondria were noted. These results provide defined in situ evidence that HIV-1 particle assembly occurs in the cytosol in addition to budding at most intracellular membranes.

Adenosine modulation of neurotransmission in human uterine arteries

The relaxing effects of adenosine, N-[(R)-1-methyl-2 phenylethyl]-adenosine (R-PIA) and 5-N-ethylcarboxamide adenosine (NECA) were investigated in human uterine arteries precontracted by phenylephrine in vitro. Adenosine, R-PIA and NECA relaxed isolated uterine arteries with intact endothelium, the potency order was NECA > R-PIA > adenosine. When tested on vessels devoid of their endothelium, the relaxing effect of adenosine was the same. These results suggest the vasodilatation effect on human uterine arteries is endothelium-independent, and might be via the A2 receptor (by pharmacological classification). By administering adenosine to human uterine arterial cell culture, single cell intracellular calcium change was also determined by laser cytometry. Decreased intracellular calcium was observed after administration of adenosine 10(-6) M and 2 x 10(-6) M. We concluded from the results that adenosine acts on human uterine artery cell by A2 receptor, independently of the endothelium, and decreases the intracellular calcium concentration, thus causing uterine artery relaxation.

Drosophila decapping protein 2 modulates the formation of cortical F-actin for germ plasm assembly

In Drosophila, the deposition of the germ plasm at the posterior pole of the oocyte is essential for the abdomen and germ cell formation during embryogenesis. To assemble the germ plasm, oskar (osk) mRNA, produced by nurse cells, should be localized and anchored on the posterior cortex of the oocyte. Processing bodies (P-bodies) are cytoplasmic RNA granules responsible for the 5'-3' mRNA degradation. Evidence suggests that the components of P-bodies, such as Drosophila decapping protein 1 and Ge-1, are involved in the posterior localization of osk. However, whether the decapping core enzyme, Drosophila decapping protein 2 (dDcp2), is also involved remains unclear. Herein, we generated a dDcp2 null allele and showed that dDcp2 was required for the posterior localization of germ plasm components including osk. dDcp2 was distributed on the oocyte cortex and was localized posterior to the osk. In the posterior pole of dDcp2 mutant oocytes, osk was mislocalized and colocalized with F-actin detached from the cortex; moreover, considerably fewer F-actin projections were observed. Using the F-actin cosedimentation assay, we proved that dDcp2 interacted with F-actin through its middle region. In conclusion, our findings explored a novel function of dDcp2 in assisting osk localization by modulating the formation of F-actin projections on the posterior cortex.

Building a predictive model for warfarin dosing via machine learning

Background

Warfarin titration via International Normalised Ratio (INR) monitoring can be a challenge for patients on long term anticoagulation due to its multiple drug interactions, long half life and patient's individual reponse, yet critically important due to its narrow therapeutic index. Machine learning may have a role in learning and replicating existing warfarin prescribing practices, to be potentially incorporated into an automated warfarin titration model.

Purpose

We aim to explore the feasibility of using machine learning to develop a model that can learn and predict actual warfarin titration practices.

Methods

A retrospective dataset of 4,247 patients with 48,895 data points of INR values were obtained from our institutional database. Patients who had less than 5 visits recorded, invalid or missing values were excluded. Variables studied included age, warfarin indication, warfarin dose, target INR range, actual INR values, time between titration and time in therapeutic range (TTR as defined by the Rosenthal formula).

The machine learning model was developed on an unbiased training data set (1,805 patients), further refined on a handpicked balanced validation set (400 patients), before being evaluated on two balanced test sets of 100 patients each. The test sets were handpicked based on the criteria of TTR (“in vs out of range”) and stability of INR results (“low vs high fluctuation”) (Table 1). Given the time series nature of the data, a Recurrent Neural Network (RNN) was chosen to learn warfarin prescription practices. Long-short term memory (LSTM) cells were further employed to address the problem of time gaps between warfarin titration visits which could result in vanishing gradients.

Results

A total of 2,163 patients with 42,622 data points were studied (mean age 65±11.7 years, 54.7% male). The mean TTR was 65.4%. The total warfarin dose per week as predicted by the RNN was compared with actual total warfarin dose per week prescribed for each patient in the test sets. The coefficient of determination for the RNN in the “in vs out of range” and “low vs high fluctuation” test sets were 0.941 and 0.962 respectively (Figure 1).

Conclusion

This proof of concept study demonstrated that a RNN based machine learning model was able to learn and predict warfarin dosage changes with reasonable accuracy. The findings merit further evaluation of the potential use of machine learning in an automated warfarin titration model.

Funding Acknowledgement

Type of funding source: None

Intravesical mitoxantrone in superficial bladder cancer

Twenty-five patients with Ta-T1 transitional cell carcinoma of the bladder were treated by transurethral resection (TUR) followed by intravesical chemoprophylaxis with mitoxantrone (10 mg diluted in 50 ml normal saline) administered weekly for 6 weeks. After a mean follow-up of 12 months, 76% of patients in the whole group, 69% in the newly diagnosed patients and 89% in the group of previously relapsed patients remained relapse free. These rates compare favorably with the other prophylactic agents available. Therapy was well tolerated in most patients, with only two patients reporting grade 3 local toxicity. We conclude that mitoxantrone is an effective and safe agent for intravesical chemotherapy.

The experiences of rectosigmoid pouch as a continent urinary diversion after radical cystectomy

Thirty-five patients receiving cystectomy underwent rectosigmoid pouch. The technique of ureteral submucous implantation was described. The follow-up results were analyzed. The relationship of postoperative voiding frequency and preoperative anal closure pressure was assessed. The day and night time continence rate is 97% (34/35). There were no hydronephrosis, no ureterocolonic stricture or reflux. The complications are not unique to rectosigmoid pouch and not high when compared with other forms of urinary diversion. When the preoperative anal closure pressure reaches nearly 100 cmH2O a postoperative outcome with good quality of life will be predicted. With the advantages of high continence rate and simplicity of performance the rectosigmoid pouch will become one of the alternative forms of continent urinary diversion. For obtaining the favorable results a patient with normal renal function, good hepatic function and anal closure pressure more than 50 cmH2O is required.