Devices and techniques used to obtain and analyze three-dimensional cell cultures

Cell cultures are indispensable for both basic and applied research. Advancements in cell culture and analysis increase their utility for basic research and translational applications. A marked development in this direction is advent of three-dimensional (3D) cultures. The extent of advancement in 3D cell culture methods over the past decade has warranted referring to a single cell type being cultured as an aggregate or spheroid using simple scaffolds as "traditional." In recent years, the development of "next-generation" devices has enabled cultured cells to mimic their natural environments much better than the traditional 3D culture systems. Automated platforms like chip-based devices, magnetic- and acoustics-based assembly devices, di-electrophoresis (DEP), micro pocket cultures (MPoC), and 3D bio-printing provide a dynamic environment compared to the rather static conditions of the traditional simple scaffold-based 3D cultures. Chip-based technologies, which are centered on principles of microfluidics, are revolutionizing the ways in which cell culture and analysis can be compacted into table-top instruments. A parallel evolution in analytical devices enabled efficient assessment of various complex physiological and pathological endpoints. This is augmented by concurrent development of software enabling rapid large-scale automated data acquisition and analysis like image cytometry, elastography, optical coherence tomography, surface-enhanced Raman scattering (SERS), and biosensors. The techniques and devices utilized for the purpose of 3D cell culture and subsequent analysis depend primarily on the requirement of the study. We present here an in-depth account of the devices for obtaining and analyzing 3D cell cultures.

Hydrophobic superparamagnetic FePt nanoparticles in hydrophilic poly(N-vinylcaprolactam) microgels: a new multifunctional hybrid system

We report the synthesis of a new multifunctional colloidal hybrid system consisting of thermoresponsive amphiphilic biocompatible poly(N-vinylcaprolactam) microgels loaded with hydrophobic superparamagnetic FePt nanoparticles (NPs).

Factors predicting surgical outcome of thymectomy in myasthenia gravis: A 16-year experience

Aim:

To assess the surgical outcome of myasthenia gravis (MG) following thymectomy and to determine the outcome predictors to such therapeutic approach.

Materials and Methods:

This study is a retrospective review of 80 consecutive thymectomies performed for MG over a 16-year period.

Results:

There were 41 females and 39 males (mean age, 34.32 years) with mean disease duration of 17.45 months prior to surgery. Stagewise distribution of the patients revealed 2.5% in stage I, 48.7% in stage IIA, 33.8% in stage IIB, 8.7% in stage III, and 6.3% in stage IV. The surgical approach was either trans-sternal (n=67) or video-assisted thoracoscopic route (n=13). Follow-up was obtained in 91.2% (n=73) of patients with mean duration of 67.7 months. At their last follow-up, 26.0% were in complete remission, 35.6% were asymptomatic on decreased medications, and 17.8% had clinical improvement on decreased medications. Overall, 79.4% of patients benefited from surgery, 8.2% had unchanged disease status, and 12.3% worsened clinically. Factors influencing favorable outcome include sex, disease stage, gland weight, and preoperative medication with anti-cholinesterase (P<0.05). There was one death in the perioperative period due to septicemia. Two patients died at fourth and seventh month following thymectomy.

Conclusion:

Thymectomy for MG is safe and effective. Certain influencing factors may shape treatment decisions and target higher risk patients.

Ease of Proseal Laryngeal Mask Airway insertion and its fibreoptic view after placement using Gum Elastic Bougie: a comparison with conventional techniques

The Proseal Laryngeal Mask Airway (PLMA) is routinely inserted by the digital and introducer tool techniques but a newer Gum Elastic Bougie (GEB) guided insertion technique has been described. The aims and objectives were to compare the ease of PLMA insertion and fibreoptic view of PLMA after placement using GEB and conventional techniques. Ninety-six ASA I or II patients of either gender aged 18 to 60 years, scheduled for elective surgery under general anaesthesia in the supine position were included in this study. Following induction of anaesthesia, a PLMA was inserted using a GEB, introducer tool or digital technique in Groups G, I and D respectively (n = 32). Correct placement of the PLMA was confirmed by using clinical tests along with fibreoptic assessment. Ease of PLMA insertion was assessed by the number of attempts, time taken and number of patients requiring lateral approach for insertion. The fibreoptic view of PLMA placement through the airway tube was graded on a scale from 4 (best view) to 1 (worst view). GEB-guided PLMA insertion was more successful both after the first attempt (G 100%, I 69%, D 72%, P < 0.01) and after two attempts (G 100%, I 78%, D 84%, P < 0.05). Time taken for successful placement was significantly shorter in the GEB-guided group after two attempts (G 22 +/- 2 seconds, I 31.9 +/- 18.8 seconds, D 29.5 +/- 18.6 seconds, P < 0.05). The fibreoptic view through the airway tube was significantly better in the GEB-guided group (P < 0.01). Incidence of trauma was significantly less in the GEB-guided group (P < 0.05).

Study of metallo-beta-lactamase production in clinical isolates of Pseudomonas aeruginosa

A study of metallo-beta-lactamase (MBL) production was done in clinical isolates of Pseudomonas aeruginosa. Isolates resistant to ceftazidime and imipenem were screened for MBL production by double disc synergy test (DDST) and minimum inhibitory concentration reduction test. There was complete correlation between two methods for imipenem. For ceftazidime, there was correlation between the two methods in all except four strains. In the screening test for MBL, ceftazidime-EDTA combination was better than imipenem-EDTA combination. 8.05% strains were MBL producers. Presence of MBL producer P. aeruginosa is a cause of concern. Simple DDST can be helpful for monitoring of these emerging resistant determinants.

Hepatopulmonary syndrome

Hepatopulmonary syndrome (HPS) is defined as clinical triad of advanced liver disease, arterial deoxygenation and intra pulmonary vascular dilatation. It is a rare complication of liver disease of varied etiology and indicates a poor prognosis. Many theories have been put forward to throw light over its pathogenesis. The major clinical manifestations are arterial hypoxemia, clubbed fingers and spider navei. Orthodeoxia and platypnea are usual clinical features. A simple non invasive method to screen HPS is desirable. Contrast enhanced 2D ECHO cardiography is the preferred screening test. No effective medical treatment has been found. Although liver transplant seems feasible to reverse (at least partially) this situation, however it is associated with increased post operative morbidity and mortality.

Emergence and re-emergence of Vibrio cholerae 0139: an epidemiological study during 1993-2002 at Nagpur, Central India

The pattern of Vibrio cholerae 01 and 0139 isolates at Indira Gandhi Medical College and Mayo General Hospital, Nagpur from 1993 to 2002 is presented. Emergence of the novel serotype 0139 in 1993 was followed by periods of quiescence and re-emergence. For the first time after 1993, the 0139 isolates out numbered 01 isolates in 2001. The peculiar epidemiological pattern is compared with other reports.

An unusually high occurrence of Salmonella enterica serotype paratyphi A in patients with enteric fever

BACKGROUND & OBJECTIVES

Salmonella enterica serotype Paratyphi A has been reported less frequently as a causative agent of enteric fever. Reports on the antimicrobial susceptibility of this pathogen are few and varied. An unusually high occurrence of S. Paratyphi A was noted in a tertiary care hospital at Nagpur, Maharashtra during April 2001-September 2002. An effort was made to study the antimicrobial susceptibility pattern and phage types of the isolates.

METHODS

Blood cultures of patients suspected to have enteric fever admitted to the Indira Gandhi Medical College and Hospital, Nagpur were processed by conventional methods. Antimicrobial susceptibility was tested by Kirby-Bauer disc diffusion method and the minimum inhibitory concentration (MIC) to chloramphenicol was determined.

RESULTS

Eighteen (46.15%) of 39 Salmonella isolates were S. Paratyphi A and all were sensitive to ciprofloxacin and cephotaxime. Twelve (66.67%) strains were sensitive to ampicillin and 13 (72.22 %) to chloramphenicol. Two strains (11.11%) were resistant to three drugs (ampicillin, chloramphenicol and cotrimoxazole) simultaneously. The prevalent phage type in the local population was phage type I.

INTERPRETATION & CONCLUSION

The high occurrence of S. Paratyphi A found in the present study indicated the emergence of this rare pathogen of enteric fever in the local population. Though some degree of resistance was encountered with ampicillin and chloramphenicol, all the isolates were sensitive to ciprofloxacin, currently a drug of choice for enteric fever. Multidrug resistance was rare.

Treatment of Indian visceral leishmaniasis with single or daily infusions of low dose liposomal amphotericin B: randomised trial

OBJECTIVE

To test short course, low dose liposomal amphotericin B as single or daily infusion treatment in Indian visceral leishmaniasis (kala-azar).

DESIGN

Randomised, open label study.

SETTING

Inpatient unit for leishmaniasis in Bihar, India.

PARTICIPANTS

91 adults and children with splenic aspirate positive for infection.

INTERVENTIONS

Total dose of 5 mg/kg of liposomal amphotericin B given as a single infusion (n=46) or as once daily infusions of 1 mg/kg for five days (n=45).

MAIN OUTCOME MEASURES

Clinical and parasitological cure assessed 14 days after treatment and long term definitive cure (healthy, no relapse) at six months.

RESULTS

All but one person in each group had an initial apparent cure. During six months of follow up, three patients in the single dose group and two in the five dose group relapsed. Complete response (definitive cure) was therefore achieved in 84 of 91 subjects (92%): 42 of 46 patients in the single dose group (91%, 95% confidence interval 79% to 98%) and 42 of 45 in the five dose group (93%, 82% to 99%). Response rates in the two groups were not significantly different.

CONCLUSION

Low dose liposomal amphotericin B (5 mg/kg), given either as a five day course or as a single infusion, seems to be effective for visceral leishmaniasis and warrants further testing.

Role of distributed amplification in designing high-capacity soliton systems

We discuss the importance of distributed amplification for high-speed soliton communication systems through numerical simulations by considering the distributed gain provided by stimulated Raman scattering or erbium dopants. Hybrid amplification schemes are also considered. At a bit rate of 40 Gb/s, the use of distributed amplification is found to improve the transmission distance (deduced from the Q parameter) by a factor of up to three for Raman amplification and >5 for erbium dopants, compared with the case of lumped amplifiers. The increase in transmission distance is by a factor of about two for 80-Gb/s soliton systems when dense dispersion management is used.

Occult breast carcinoma: a report of four cases and review of literature

We report four occult carcinoma breast cases in which extensive axillary node metastases was the first manifestation. Upper outer quadrentectomy with axillary dissection was done in three patients while modified radical mastectomy was done in one. Primary tumor could be found in three patients, one had squamous cell carcinoma (SCC) & two had infiltrating duct carcinoma (IDC). However primary tumor was not detected in breast tissue of the fourth patient. Extensive lymph node metastases were found in three out of 14,15 out of 15(SCC), 24 out of 24 and 1 out of three axillary nodes respectively. Results of immunohistochemical staining for estrogen and progesterone receptors on three cases were negative. All patient received postoperative radiotherapy and chemotherapy. We have reviewed the literature and discussed the approach to diagnosis and management in female patients presenting with metastatic carcinoma in the axillary nodes with emphasis on the appropriate pre-treatment evaluation.

Squamous cell carcinoma of thyroid gland

We present the clinical manifestation, management and outcome in two cases of squamous cell cancer arising in the thyroid gland which is a rare entity. Both cases had advanced disease invading adjacent structures. At the followup of three to six months, one patient developed recurrence and died.

Managed care companies and the practice of medicine

One of the major issues pertaining to the pending legislation for Patient's Bill of Rights is the potential of liability health care plans, particularly when they decline coverage they consider not medically necessary. We call these contracts "managed health care" plans. But, realistically, when is it managing? When is it medicine? When, if at all, does management undermine medicine? And if it does, should managed care organizations--and their representatives--be held legally liable for medical decisions that go wrong? A panel of seven experts examines these questions from medical, payment, patient, legal, insurance, and governing viewpoints.

Short-course of oral miltefosine for treatment of visceral leishmaniasis

A total of 54 Indian patients with visceral leishmaniasis were treated with oral miltefosine, 50 mg given twice daily, for 14 days (18 patients; group A), 21 days (18; group B), or 28 days (18; group C). Cure was achieved in 89% of group A, 100% of group B, and 100% of group C. Adverse reactions were self-limited and primarily mild. The 21-day miltefosine regimen combines high-level efficacy, convenient dosing, and a relatively short duration.

Short-course, cost-effective treatment with amphotericin B-fat emulsion cures visceral leishmaniasis

Although short-course therapy with new lipid formulations of amphotericin B represents an advance over lengthy traditional treatments in visceral leishmaniasis (kala-azar), high cost has rendered these agents largely irrelevant in developing countries where the disease is endemic. Therefore, we tested standard amphotericin B deoxycholate mixed with a commercial fat emulsion as short-course treatment for Indian visceral leishmaniasis in Bihar in 1997/98. Seventy children and adults with splenic aspirate-documented infection, 23 of whom had failed prior antimony (Sb) therapy, received 5 alternate-day infusions of 2 mg/kg. Apparent cure, which required a parasite-free splenic aspirate smear, was assessed 20 days after treatment (day 30); definitive cure was determined at 6 months. Other than anticipated infusion-related fever and/or chills, treatment was safe and well tolerated. One patient required dose modification because of mild, reversible renal insufficiency. Sixty-nine patients (98.6%, CI 92.3-100%) had apparent cures; during follow-up, there were 4 treatment failures (relapses, 3; unrelated death, 1), yielding definitive cures in 65 of 70 patients (92.9%, CI 84.1-97.6%). Including retreatment costs for patients in Bihar (who now often fail initial Sb therapy), the final per patient cost of the tested regimen (US $260) was 59% and 43% less than treatment with Sb or conventional amphotericin B alone, respectively. Short-course treatment with amphotericin B-fat emulsion is active, cost-effective treatment for patients with visceral leishmaniasis including those with Sb-unresponsive infection.

Robust optical control of an optical-amplifier-based flip-flop

We demonstrate new optical techniques for externally controlling the latchable output power of a semiconductor-optical-amplifier-based flip-flop. Optical 'set' and 'reset' signals increase and decrease the re-fractive index, respectively, via cross-phase modulation (XPM). Set signals, which deplete the carrier density, have wavelengths between 1533 and 1568 nm, and powers as low as 22 microW. Reset is performed with carrier-generating 'positive' optical pulses at 1306 and 1466 nm, and minimum powers below 1 mW. These techniques are useful for digital optical-processing functions such as bit-length conversion, retiming, and demultiplexing.

Introduction

Several recent developments have resulted in considerable progress in the study of transverse effects and spatial mode dynamics in semiconductor lasers. Demands on higher and higher output powers have led to the development of wide-stripe lasers, coupled laser arrays, integrated master-oscillator power amplifiers (MOPAs), and other more complex laser structures for which spatial dependence of the laser mode becomes important. This is especially true for the vertical-cavity surface-emitting lasers (VCSELs), devices that have recently become commercially available and are being proposed for a multitude of interesting applications. In the case of a VCSEL, the transverse-mode behavior is inherently more complex compared with the traditional edge-emitting lasers because of a large Fresnel number associated with VCSELs. The recent interest in spatio-temporal dynamics of such lasers as an example of well-controlled, spatially extended, self-organizing systems has led to new understanding about patterns, defects, and other coherent and incoherent structures, all being important to large-aperture diode lasers.

Low-power all-optical switching in active semiconductor chirped periodic structures

We investigate the effects of spatial chirp of the built-in grating on the spectral range and switching power of all-optical switching in active semiconductor periodic structures. We show that a total linear variation in the grating period of as little as 0.24% nearly triples the spectral range of low-power switching. Moreover, the upward-switching power at the onset of bistability is lowered by two orders of magnitude, to a value below 10 nW for typical device-parameter values. These improvements occur for optical signals tuned to the long-wavelength side of the stop band and propagating in the direction of increasing grating period. We also predict the existence of multiple bistable hystereses in devices with large amounts of spatial chirp.

High-repetition-rate soliton-train generation using fiber Bragg gratings

We propose a high-repetition-rate soliton-train source based on adiabatic compression of a dual-frequency optical signal in nonuniform fiber Bragg gratings. As the signal propagates through the grating, it is reshaped into a train of Bragg solitons whose repetition rate is predetermined by the frequency of initial sinusoidal modulation. We develop an approximate analytical model to predict the width of compressed soliton-like pulses and to provide conditions for adiabatic compression. We demonstrate numerically the formation of a 40-GHz train of 2.6-ps pulses and find that the numerical results are in good agreement with the predictions of our analytical model. The scheme relies on the dispersion provided by the grating, which can be up to six orders of magnitude larger than of fiber and makes it possible to reduce the fiber length significantly.

Usefulness of combined color Doppler/contrast in providing complete delineation of left ventricular cavity

Contrast-enhanced 2-dimensional echocardiography without color Doppler did not result in complete filling of the left ventricular cavity in 21 patients studied. However, contrast-enhanced color Doppler was very effective and provided complete opacification of the left ventricular cavity in 20 of these 21 patients.

An improved flow evaluation scheme in orifices of different aspect ratios

An accurate and reliable method of regurgitant flow calculation is currently unavailable. The goal of this study was to define a new general method of flow calculation for orifices of different aspect ratios. The success of the method relies on matching the imaged flow field distribution obtained by color flow mapping (CFM) to a three-dimensional (3D) numerical flow field distribution of known geometry. The flow field in three orifices of identical cross-sectional area with aspect ratios of 1 (circular), 2 and 4 (elliptical) was evaluated by: (a) CFM, (b) 3D echocardiographic imaging, and (c) 3D finite element modeling (FEM). The orifice shape and size were accurately estimated by 3D echocardiographic imaging. FEM showed that the normalized centerline velocity profile of the flow field depends on the orifice aspect ratio. CFM provided a good description of the centerline profile for each case. For a given distance from the orifice center, the equivelocity contour surface area increases with increasing aspect ratio. A simple flow calculation scheme was developed to calculate regurgitant flow independent of orifice shape. This improved method showed better results than previous studies and may prove to be advantageous when analyzing in vivo flow fields with complex geometries.

Intra nuclear estrogen receptor status and its clinicopathological correlation in breast cancer patients

Intranuclear estrogen receptor (ERn) content of breast cancer tissue is thought to be more closely related to prognosis, and response to hormone treatment, as compared to conventional cytosolic estrogen receptor (REc). ERn and ERc levels in primary breast carcinoma tissue were assayed by ER-Enzyme immuno assay (ER-EIA), and the correlation of ERn with ERc and clinico-pathological parameters were assessed. ERn concentration and positive status, with 15 fmol as the cut-off value for positivity, is related to increasing age, lesser parity, post-menopausal status and smaller tumor size. A significant correlation exists between ERn and lesser metastatic axillary nodes and the early TNM stage. ERn was found to be correlated to better tumor differentiation, absent or slight L-R response and tumor necrosis.