A microfluidic platform for functional testing of cancer drugs on intact tumor slices

Present approaches to assess cancer treatments are often inaccurate, costly, and/or cumbersome. Functional testing platforms that use live tumor cells are a promising tool both for drug development and for identifying the optimal therapy for a given patient, i.e. precision oncology. However, current methods that utilize patient-derived cells from dissociated tissue typically lack the microenvironment of the tumor tissue and/or cannot inform on a timescale rapid enough to guide decisions for patient-specific therapy. We have developed a microfluidic platform that allows for multiplexed drug testing of intact tumor slices cultured on a porous membrane. The device is digitally-manufactured in a biocompatible thermoplastic by laser-cutting and solvent bonding. Here we describe the fabrication process in detail, we characterize the fluidic performance of the device, and demonstrate on-device drug-response testing with tumor slices from xenografts and from a patient colorectal tumor.

Retraction: Néel Spin-Orbit Torque Driven Antiferromagnetic Resonance in Mn_{2}Au Probed by Time-Domain THz Spectroscopy [Phys. Rev. Lett. 120, 237201 (2018)]

Retraction of DOI: 10.1103/PhysRevLett.120.237201.

Néel Spin-Orbit Torque Driven Antiferromagnetic Resonance in Mn_{2}Au Probed by Time-Domain THz Spectroscopy

We observe the excitation of collective modes in the terahertz (THz) range driven by the recently discovered Néel spin-orbit torques (NSOTs) in the metallic antiferromagnet Mn_{2}Au. Temperature-dependent THz spectroscopy reveals a strong absorption mode centered near 1 THz, which upon heating from 4 to 450 K softens and loses intensity. A comparison with the estimated eigenmode frequencies implies that the observed mode is an in-plane antiferromagnetic resonance (AFMR). The AFMR absorption strength exceeds those found in antiferromagnetic insulators, driven by the magnetic field of the THz radiation, by 3 orders of magnitude. Based on this and the agreement with our theory modeling, we infer that the driving mechanism for the observed mode is the current-induced NSOT. Here the electric field component of the THz pulse drives an ac current in the metal, which subsequently drives the AFMR. This electric manipulation of the Néel order parameter at high frequencies makes Mn_{2}Au a prime candidate for antiferromagnetic ultrafast memory applications.

Continuous-flow multi-pulse electroporation at low DC voltages by microfluidic flipping of the voltage space topology

Concerns over biosafety, cost, and carrying capacity of viral vectors have accelerated research into physical techniques for gene delivery such as electroporation and mechanoporation. Advances in microfabrication have made it possible to create high electric fields over microscales, resulting in more efficient DNA delivery and higher cell viability. Continuous-flow microfluidic methods are typically more suitable for cellular therapies where a large number of cells need to be transfected under sterile conditions. However, the existing continuous-flow designs used to generate multiple pulses either require expensive peripherals such as high-voltage (>400 V) sources or function generators, or result in reduced cell viability due to the proximity of the cells to the electrodes. In this paper, we report a continuous-flow microfluidic device whose channel geometry reduces instrumentation demands and minimizes cellular toxicity. Our design can generate multiple pulses of high DC electric field strength using significantly lower voltages (15-60 V) than previous designs. The cells flow along a serpentine channel that repeatedly flips the cells between a cathode and an anode at high throughput. The cells must flow through a constriction each time they pass from an anode to a cathode, exposing them to high electric field strength for short durations of time (the "pulse-width"). A conductive biocompatible poly-aniline hydrogel network formed in situ is used to apply the DC voltage without bringing the metal electrodes close to the cells, further sheltering cells from the already low voltage electrodes. The device was used to electroporate multiple cell lines using electric field strengths between 700 and 800 V/cm with transfection efficiencies superior than previous flow-through designs.

Correction: Weak backbone CH⋯OC and side chain tBu⋯tBu London interactions help promote helix folding of achiral NtBu peptoids

Correction for ‘Weak backbone CH⋯OC and side chain tBu⋯tBu London interactions help promote helix folding of achiral NtBu peptoids’ by G. Angelici et al., Chem. Commun., 2016, 52, 4573–4576.

Weak backbone CH⋯OC and side chain tBu⋯tBu London interactions help promote helix folding of achiral NtBu peptoids

The synthesis and helix folding propensity of achiral all-cis amide (NtBu)-glycine oligomers is reported.

Prevalence and significance of antiphospholipid antibodies in selected at-risk obstetrics cases: a comparative prospective study

In a prospective comparative study we screened 112 women with a past history either of pre-eclampsia, eclampsia, recurrent abortion, IUGR, IUFD or abruptio placentae, with no apparent aetiology and a demographically matched cohort of 106 women having a past history of uncomplicated pregnancy outcome for the presence of antiphospholipid antibodies (aPL) and their significance. In the former group, the prevalence of aPL ranged from 10-46.87% compared with 8.49% in the later group. In women with the presence of aPL, the incidence of pre-eclampsia, early onset pre-eclampsia and abruptio placentae were 25%, 14.58% and 18.75%, respectively. In the same group, the abortion rate was 25% and live-birth rate was 64.58% with IUFD rate of 10.42%. Fetal morbidity rates were also higher in the mothers with aPL positivity, the incidence of IUGR was 27.08% and oligohydramnios was 33.33% in them. All these complications were statistically significant when compared with those of aPL negative mothers.

Efficacy of a plant extract (Chelidonium majus L.) in combating induced hepatocarcinogenesis in mice

Ethanolic whole plant extract of Chelidonium majus, extensively used in traditional systems of medicine against various liver ailments, has been tested for its possible anti-tumor, hepato-protective and anti-genotoxic effects in p-dimethylaminoazobenzene (p-DAB) induced hepatocarcinogenesis in mice through multiple assays: cytogenetical, biochemical, histological and electron microscopical. Different sets of mice, 5 (for 7, 15 and 30 days' treatment) or 10 (for 60, 90 and 120 days) each, were chronically fed a diet suitably mixed with p-DAB and phenobarbital to develop liver tumors. One sub-group of carcinogen fed mice was also fed C. majus extract; 0.1 ml daily (drug-treated) while the other equal amount of dilute ethyl alcohol ("vehicle" of plant extract) (positive control). A separate group of mice was maintained with normal diet without any carcinogen treatment (negative control). Data of several cytogenetical endpoints and biochemical assay of some toxicity marker enzymes at all fixation intervals and histology of liver sections through ordinary, scanning and transmission electron microscopy at 60 and 120 days and that of spleen and kidney at 90 days were critically analyzed in the treated lots vis-a-vis controls. The results suggest anti-tumor, anti-genotoxic and hepato-protective effects of the plant extract, showing potentials for use in cancer therapy.

Colostomy shift en masse--a new procedure

Colostomy shift en masse is a novel technique in which the colostomy is shifted along with a rim of skin and abdominal wall tissue. This provides additional length of distal bowel if needed during pull-through anastomosis. We have treated three cases (two Hirschsprung's disease and one anorectal malformation) with colostomy shift en masse, and have achieved good results.

Anal shift: preliminary results

BACKGROUND/PURPOSE

Perineal ectopic anus in female infants is not a very uncommon congenital anomaly. The close proximity of the ectopic anus with the vulva and the stenosed opening seen in large majority of cases necessitate some form of surgical correction. A variety of surgical procedures like cutback, posterior anal transposition, PSARP, or ASAPR, with or without diverting colostomy have been described in the literature. However, in dealing with a case of ectopic anus, the authors thought a much simpler surgical correction would suffice giving an aesthetically and functionally acceptable perineum. This new and simple surgical procedure developed by Ashok Shah, Anal Shift is described in this report.

METHODS

Twelve female infants with anterior ectopic anus, between 3 and 18 months of age who had undergone surgical correction by this new method (Anal Shift) is reported. Five of these children had severe and 2 had mild anal stenosis. The new technique described in detail includes shifting and creation of a new anus in the anatomically normal site and construction of the perineal body. Colostomy was not done in any of them.

RESULTS

The cases had been followed up for 12 to 24 months. Anal function was normal with satisfactory vulvo-anal distance without any stenosis. One patient had superficial anterior wound dehiscence; she underwent reoperation with good results.

CONCLUSIONS

Anal Shift is a simple surgical procedure. It does not necessitate lateral dissection, therefore, the rectal support and the neurovascular supply to the rectum remains undisturbed, eliminating any chance of retraction. The anterior half of the neoanus does not have a suture line, thereby minimizing the chances of stricture formation. Anal Shift appears to be a safe, simple and satisfactory surgical procedure to correct anterior ectopic anus in girls without a colostomy.

Recurrent respiratory papillomatosis: a study of 24 cases

24 cases of recurrent respiratory papillomatosis (RRP) in children were treated by surgical removal with cup forceps and followed up for variable periods between 1990-95. Most of the patients required multiple operations due to recurrence. No anaesthetic death or complication was recorded. Voice changes of different degrees were noted. Four patients has glottic web formation. The findings suggest that recurrence of RRP is very common & needs multiple session of surgery. For children with persistent and progressive voice change/cry, the necessity of precise & comprehensive endoscopic examination of the upper aerodigestive tract under general anesthesia (GA) is emphasized.

Comparison of no medication, placebo, and hyoscyamine for reducing pain during a barium enema

OBJECTIVE

We carried out a prospective, randomized study to evaluate the usefulness of premedication with an oral anticholinergic for relief of pain during and after a barium enema of the colon.

SUBJECTS AND METHODS

Patients were randomized into three groups: no medication, placebo, and sublingual 1-hyoscyamine sulfate. The placebo or hyoscyamine tablet was placed under the tongue 15-30 min before the examination. After the procedure the patients were interviewed. An analog scale (0-10) was used to score the level of pain that the patients experienced during the examination. Forty-eight hours after the examination, the patients returned by mail a survey that used the same scale and asked about delayed pain.

RESULTS

Data from 110 patients were studied. Sixty-nine patients were women, and 41 were men. They ranged from 24 to 82 years old (mean, 55 years). For the no-medication group (n = 36), the mean pain score was 4.1; for the placebo group (n = 34), 3.8; and for the hyoscyamine group (n = 40), 4.2. No statistically significant difference in pain scores was found between any groups (p = .72). Six patients from each group reported minor side effects. The mean scores from the returned surveys (n = 79) were 3.8 for the no-medication group (n = 26) and placebo group (n = 22) and 3.1 for the hyoscyamine group (n = 31). No statistically significant difference was found between any of these groups (p = .48) or between delayed pain responses and initial pain responses (p = .27).

CONCLUSION

Although safe, hyoscyamine seems to provide no benefit over no drug or a placebo when used as a pain premedication for patients undergoing a barium enema.

Dystrophic calcification in the neck--a case report

One 55 years aged male person was admitted with progressive painless neck swelling with multiple discharging sinuses. His X-ray of the neck showed a dense radio-opaque shadow & serum calcium level was 2 mmol/l. On neck exploration, an irregular calculus was revealed; hooking around the left carotid sheath. Histopathology confirmed the clinical diagnosis of tuberculosis. Anti-TB chemotherapy for six months cured him.

Multiple papilloma of the larynx in an adult--a case report

Multiple papilloma of the larynx commonly affects the juvenile subjects. Only a few adult cases have been reported. Such a rare case in Bangladesh, is reported here. Twenty five years old one male patient was admitted into Sir Salimullah Medical College & Mitford Hospital with the complaints of hoarseness of voice & dysponea. He was diagnosed as papilloma clinically and histopathologically, and treated with tracheostomy & microlaryngoscopic excision of the masses. The patient was readmitted after 3 months with recurrence of papilloma at the same site and the growth was excised under anaesthesia. The past history of his illness revealed that he underwent to more surgeries for the same condition. The patient was lost to follow up.

Cut throat injury: a retrospective study of 26 cases

Cut throat injuries and associated deaths are common in our society. Majority succumb to their injuries. In this study, the hospital records of twenty six such cases (13 M & 13 F) were reviewed. Eleven victims were in their third decade. Eighteen cases came from poor socio-economic class. Eleven had suicidal, eleven homicidal and four accidental injuries. Familial troubles, psychiatric illness and poverty were the triggering factors in suicidal attempts. The motives of homicide included political conflict, sex related crimes, dacoity, familial, land related disputes, etc. All had their hypopharynx and/or larynx exposed. Tracheostomy was done in fifteen cases. All but two had uneventful recovery. One died in the hospital due to hemorrhage, shock and asphyxia from aspirated blood. It was observed that appropriate measures could save lives in vast majority.

A wooden foreign body in the neck

Foreign bodies in the throat and/or neck are uncommon and transpharyngeal impaction of a wooden foreign body in the neck without vascular injury is very rare. The patient presented in this communication, reported to our center five days after severe physical assault with a pharyngocutaneous fistula in the left side of the neck. Clinical examination and X-rays were unremarkable. Conservative treatment led to healing of the fistula and he was discharged. Two weeks later he was readmitted with an abscess in the right supraclavicular region. Exploration under general anaesthesia revealed a 7 cm long wooden fragment of a spear in the abscess cavity. The fragment was removed. After several days' antibiotic treatment, he recovered fully and was discharged.

Febrile episode among a floating population of C.R.P.F. Jawans stationed at Calcutta

A virological investigation was carried out to establish the etiologic agent of a febrile outbreak amongst a floating population of C.R.P.F. Jawans, stationed at Calcutta during May-July, 1993. The illness was associated with fever, severe headache, bodyache and arthralgia which lasted for 2-4 days in most of the cases. Fifty cases were examined clinically and blood samples (both acute and convalescent) were subjected to virological study. One mouse-pathogenic agent could be isolated in suckling mice and identified as DEN-3. Sero-investigation of 50 single sera by HI & CF method revealed evidence of presumptive dengue infection in 33, while sero-conversion could be noted in 10 out of 25 available paired sera tested. Results of MAC ELISA revealed evidence of primary dengue infection in 6 out of 12 acute phase sera examined. Thus, the study shows that the episode is strongly suggestive of primary dengue infection.

Fractured tracheostomy tubes: 3 case reports

Although tracheobronchial foreign bodies are not rare, fractured tracheostomy tubes presenting as such, is rare indeed. Three such cases (one metallic and two Polyvenyl Chloride (P.V.C. tubes) are reported here. These foreign bodies were removed bronchoscopically with uneventful recovery.

Dengue haemorrhagic fever (DHF) outbreak in Calcutta--1990

An outbreak of Dengue Haemorrhagic Fever (DHF) occurred in Calcutta between September and December, 1990. Children and young adults were the major victims. Haemorrhagic manifestations and shocks were the main features in most of the hospitalised cases. Five mouse pathogenic agents were isolated from 105 acute cases and all were identified as DEN-3. HI and CF test with 55 paired sera revealed evidence of dengue infection in 33 (60 per cent) and flavivirus group reaction including dengue in 17 (30.9 per cent). It was for the first time, that DEN-3 was considered to be the etiologic agent for DHF in Calcutta.