Spatial Multiplexing of Whispering Gallery Mode Sensors

Whispering gallery mode resonators have proven to be robust and sensitive platforms for the trace detection of chemical and/or biological analytes. Conventional approaches using serially addressed resonators face challenges in simultaneous multi-channel (i.e., multi-species) detection. We present an alternative monitoring scheme that allows for the spatial multiplexing of whispering gallery mode resonators with the simultaneous observation of the resonance spectra from each of them. By imaging arrays of microspheres and monitoring the glare spot intensities through image processing routines, resonance spectra from multiple resonators may be simultaneously recorded without interference or confounding effects of serial excitation/detection. We demonstrate our multiplexed imaging approach with bulk refractive index variations and virus-antibody binding.

Myrcene and terpene regulation of TRPV1

Nociceptive Transient Receptor Potential channels such as TRPV1 are targets for treating pain. Both antagonism and agonism of TRP channels can promote analgesia, through inactivation and chronic desensitization. Since plant-derived mixtures of cannabinoids and the Cannabis component myrcene have been suggested as pain therapeutics, we screened terpenes found in Cannabis for activity at TRPV1. We used inducible expression of TRPV1 to examine TRPV1-dependency of terpene-induced calcium flux responses. Terpenes contribute differentially to calcium fluxes via TRPV1 induced by Cannabis-mimetic cannabinoid/terpenoid mixtures. Myrcene dominates the TRPV1-mediated calcium responses seen with terpenoid mixtures. Myrcene-induced calcium influx is inhibited by the TRPV1 inhibitor capsazepine and Myrcene elicits TRPV1 currents in the whole-cell patch-clamp configuration. TRPV1 currents are highly sensitive to internal calcium. When Myrcene currents are evoked, they are distinct from capsaicin responses on the basis of Imax and their lack of shift to a pore-dilated state. Myrcene pre-application and residency at TRPV1 appears to negatively impact subsequent responses to TRPV1 ligands such as Cannabidiol, indicating allosteric modulation and possible competition by Myrcene. Molecular docking studies suggest a non-covalent interaction site for Myrcene in TRPV1 and identifies key residues that form partially overlapping Myrcene and Cannabidiol binding sites. We identify several non-Cannabis plant-derived sources of Myrcene and other compounds targeting nociceptive TRPs using a data mining approach focused on analgesics suggested by non-Western Traditional Medical Systems. These data establish TRPV1 as a target of Myrcene and suggest the therapeutic potential of analgesic formulations containing Myrcene.

Deletion of Fas protects islet beta cells from cytotoxic effects of human islet amyloid polypeptide

AIMS/HYPOTHESIS: Islet amyloid, which is mainly composed of human islet amyloid polypeptide (hIAPP), is a pathological characteristic of type 2 diabetes and also forms in cultured and transplanted islets. We used islet beta cells as well as two ex vivo models of islet amyloid formation, cultured human islets and hIAPP-expressing transgenic mouse islets with or without beta cell Fas deletion, to test whether: (1) the aggregation of endogenous hIAPP induces Fas upregulation in beta cells; and (2) deletion or blocking of Fas protects beta cells from amyloid toxicity. METHODS: INS-1, mouse or human islet cells were cultured with hIAPP alone, or with amyloid inhibitor or Fas antagonist. Non-transduced islets, and human islets or hIAPP-expressing mouse islets transduced with an adenovirus that delivers a human proIAPP-specific small interfering RNA (siRNA) (Ad-ProhIAPP-siRNA) were cultured to form amyloid. Mouse islets expressing hIAPP with or without Fas were similarly cultured. Beta cell Fas upregulation, caspase-3 activation, apoptosis and function, and islet IL-1β levels were assessed. RESULTS: hIAPP treatment induced Fas upregulation, caspase-3 activation and apoptosis in INS-1 and islet cells. The amyloid inhibitor or Fas antagonist reduced apoptosis in hIAPP-treated beta cells. Islet cells with Fas deletion had lower hIAPP-induced beta cell apoptosis than those expressing Fas. Ad-ProhIAPP-siRNA-mediated amyloid inhibition reduced Fas upregulation and IL-1β immunoreactivity in human and hIAPP-expressing mouse islets. Cultured hIAPP-expressing mouse islets with Fas deletion had similar amyloid levels, but lower caspase-3 activation and beta cell apoptosis, and a higher islet beta:alpha cell ratio and insulin response to glucose, compared with islets expressing Fas and hIAPP. CONCLUSIONS/INTERPRETATION: The aggregation of biosynthetic hIAPP produced in islets induces beta cell apoptosis, at least partially, via Fas upregulation and the Fas-mediated apoptotic pathway. Deletion of Fas protects islet beta cells from the cytotoxic effects of endogenously secreted (and exogenously applied) hIAPP.

[Efficiency of a postoperative treatment after rotator cuff repair with a continuous passive motion device (CPM)]

AIM

The main objective of this study was to prove that a postoperative combined continuous passive motion (CPM) and physiotherapy treatment protocol (CPM group) can achieve 90 degrees active abduction in the shoulder joint earlier than physiotherapy alone (PT group). The indication was a complete tear of the rotator cuff.

METHOD

The study was conducted under in-patient and out-patient conditions. 55 patients were included in this study. The prospective, randomized multicenter study design complies with DIN EN 540. The primary endpoint was the time span until 90 degrees active abduction was achieved by the patients.

RESULTS

Patients in the CPM group reached the primary endpoint on average 12 days earlier than the control group. This difference was statistically significant (p = 0.0292). Analyzing the secondary endpoints, e. g., pain and disablement, the results in the CPM group showed again advantages of the combined treatment protocol (CPM + physiotherapy).

CONCLUSION

The postoperative treatment of a total tear of the rotator cuff with a combined continuous passive motion and physiotherapy protocol provided a significantly earlier range of motion in the shoulder joint than physiotherapy alone. There was no report of CPM-related adverse effects.

[Modeling light distribution in nasal tissue structures]

There are different applications in the field of optical diagnostics in which the theories explaining the light transport in tissue do not lead to simple solutions for complicate geometric conditions. In these cases the Monte Carlo method provides a powerful tool to solve this problem statistically. In order to simulate the light transport in the nasal region a model was created which includes the structure depending on the swelling of the mucous membrane as well as the Monte Carlo model. Using this model it is possible to evaluate the measured values qualitatively. However, due to the long distance between light source and detector the statistical error becomes a major problem for reliable statements.

Rapid PCR-based identification of methicillin-resistant Staphylococcus aureus from screening swabs

A PCR identification of methicillin-resistant Staphylococcus aureus (MRSA), obviating the need for subculture on agar media, was investigated. The combination of MRSA detection by mecA femB PCR with prior enrichment in selective broth was tested for 439 swabs. PCR identified 36 MRSA-positive samples, in concordance with conventional methods.

[Medial flexor digitorum longus tendon augmentation and lateral foot column lengthening or reorienting triple arthrodesis as surgical therapy of posterior tibial tendon dysfunction]

QUESTION

The purpose of this study was to evaluate the alignment and functional outcome after surgical augmentation of the tibialis posterior by tendon transfer and lateral column lengthening by osteotomy of the os calcis, calcaneo-cuboidal arthrodesis or reorientating triple arthrodesis.

METHODS

From 1991 to 1999 41 patients with the clinical and radiological diagnosis of dysfunction of the tibialis posterior tendon underwent surgical exploration and repair. These 41 patients (22 women, 19 men) had an average age of 44.3 years (range, 19-69 years) and had been symptomatic for an average of 2.3 years (range, 6 months to 6 years). All patients had the symptoms of a painful flatfoot deformity without dynamic support along the medioplantar aspect. Flexor digitorum longus (FDL) tendon transfer as reconstruction of the tibialis posterior tendon was performed in the cases without major deformity (n = 77). Patients underwent FDL transfer and lengthening osteotomy (n = 15) of the os calcis or calcaneocuboidal (c-c) arthrodesis (n = 12) if passive correction of the foot deformity was still possible and reorientating triple arthrodesis (n = 7) when a fixed flatfoot deformity had developed. AOFAS score and radiological examination were used preoperatively and in the follow-up.

RESULTS

The AOFAS score improved for stage 1 patients after a mean follow-up of 43 months with FDL transfer from a preoperative mean of 54 to 84 points, for stage II patients with FDL transfer and lengthening osteotomy (mean follow-up 36 m) from 47 to 92 points, with c-c arthrodesis (follow-up 66 m) from 48 to 86 points, and for stage III patients with triple arthrodesis from 42 to 72 points. In two patients, the deformity failed to improve (stage I) necessitating a revision surgery with a calceneo-cuboidal lengthening arthrodesis for relapsing deformity.

CONCLUSION

In order to correct deformity and provide substantial relief of foot pain and dysfunction, we recommend the transfer of the FDL tendon in flexible flat foot deformity together with lengthening osteotomy. This treatment will provide optimal restoration of a dynamic support along the medioplantar aspect of the foot and is functionally superior to a c-c arthrodesis. Reorientating triple arthrodesis showed fair functional results and is recommended--for fixed flatfoot deformity.

Early full weightbearing and functional treatment after surgical repair of acute achilles tendon rupture

We prospectively evaluated the clinical outcomes of 20 patients (mean age, 42.8 years) with early full weightbearing and functional treatment after surgical repair of acute Achilles tendon rupture according to a prospective intra- and postoperative protocol. All patients underwent open repair using a Kessler-type suture and simple apposition sutures. The postoperative regimen included a plantigrade splint for 24 hours and 6 weeks of early full weightbearing in a removable walker. All patients were evaluated with clinical and ultrasound examination and according to a new scoring system at 3, 6, and 12 months after repair. After 3 months, the score averaged 73 of 100 points; after 6 months, 86; and after 1 year, 94. All patients reached the same level of sports activities as preoperatively and demonstrated no significant difference in ankle mobility and isokinetic strength. There were no reruptures. One patient had a deep venous thrombosis 3 weeks after the operation after having prematurely stopped thromboprophylaxis. We believe that early careful ankle mobilization and full weightbearing in a removable walker after primary Achilles tendon repair does not increase the risk of rerupture. An accelerated rehabilitation program improves early foot function with excellent recovery of plantar flexion strength and amplitude.

A cement spacer for two-stage revision of infected implants of the hip joint

We report the technical details and clinical results of twelve patients who had deep infections of implants in the hip joint and were treated by two-stage revision, using a gentamicin-loaded, hand-moulded cement spacer inserted for the period between resection and reimplantation arthroplasty. During management with the spacer, usually for 4 months, patients were almost free of pain and mobile with good leg control, spending 2/3 of the treatment period at home. Six of twelve spacers failed locally due to dislocation [5] or cement fracture [1], and more than two further episodes of surgery were required in 3 patients. Problems with dislocation of the spacer were significantly higher when the head to neck offset was lacking (P < 0.05) or when anchorage in the femoral shaft was poor. Nevertheless, infection after reimplantation arthroplasty did not occur by the time of follow-up (2.2 years). Based on these data, we consider that the use of the cement spacer is a promising approach to the treatment of complicated infections of the hip joint.

Ribosomal RNA gene dosage in marine bacteria

Ribosomal RNA gene dosage was determined for 20 marine heterotrophic bacteria using short probes (< 600 bp) from the Escherichia coli 16S rRNA gene and Southern blot analysis. All Bacterial strains had between 4 and 10 copies of the 16S rRNA genes in their genomes. This report presents important preliminary data for developing quantitative molecular methods to address population dynamics of marine based of 16S rRNA sequences.

[Arthroscopic capsulo-labral repair and refixation with Mitek anchor in anterior shoulder instability]

From May 1992 to September 1995, 38 patients with recurrent anterior shoulder instability underwent arthroscopic stabilization. The arthroscopic stabilization was performed by capsular shifting and labral refixation using Mitek anchors, based on the Wolf procedure. Immediately after operation active assisted shoulder mobilization was initiated (elevation 60 degrees, external rotation 20 degrees less than contralateral shoulder). After a mean follow-up of 24 months (12-42 months) 30 patients were evaluated by means of the Rowe Score. Excellent and good results were achieved in 90% (n = 27) of patients and 80% had no restriction in sports activities. In 4 of the patients (13%) redislocation occurred. Analysis of the recurrence revealed no adequate trauma in two patients with preoperative multidirectional laxity. One had a trauma and the fourth showed no compliance in the early postoperative period. Compared to the open Bankart operation the described procedure shows a slightly higher rate of redislocations. However, the approach is less invasive and the subscapularis tendon with its proprioception remains intact.

[4-fragment fractures of the proximal humerus. Alternative strategies for surgical treatment]

The operative treatment of dislocated fractures of the proximal humerus has been evolving in recent years. Replacement using endoprostheses often results in only moderate functional outcome, and with the high risk of aseptic necrosis with ORIF, new methods of minimally invasive stabilisation have been developed. These methods reduce the opening of the fracture site to a minimum and thereby limit the risk of iatrogenic damage to local vascularity and the rotator cuff. This study reviewed 18 patients operated on with minimal osteosynthesis for dislocated four-part fractures of the proximal humerus from March 1991 to October 1994. Only tension band wiring with resorbable cords from woven polydioxanone was applied. After an average follow-up of 26 months (20-37 months), 72% (n = 13) of the four-part fractures were rated as good and very good results according to the Neer Score. In 16.7%, a complete head necrosis occurred, requiring a prosthetic replacement. Two patients with partial necrosis (11.1%) had a good functional outcome. With regard to these results, we recommend head-preserving tension band wiring with resorbable cords and preservation of the articular surface. At the present time the procedure seems comparable with prosthetic replacement in respect of shoulder function.

[Proximal humeral multiple fragment fractures--failures after T-plate osteosynthesis]

Dislocated compound fractures of the proximal humerus are often difficult to treat. The choice of treatment influences the final functional result. From 1984-1991 108 patients with dislocated compound fractures of the proximal humerus were operated with a T-plate osteosynthesis, retrospectively examined and classified according to the Neer-Classification. At an average follow up time of 5 years 72 patients had a clinical and radiological examination. 68% of these patients with 3-fragment fractures and 80% with 4-fragment fractures showed a modest to unsatisfactory result caused by fracture biology, imprecise fracture reduction or poor surgical procedure. Incorrect position of T-plates and inadequate material were distinguishable. The T-plate which was widely used in the late eighties for internal fixation has to be considered a failure for these particular types of fractures and should be limited for Collum chirurgicum fractures.

[Classification of patellar fractures]

The AO-Classification of patellar fractures, introduced 1979 is based on difficult radiomorphologic criteria. It has never been widely accepted. The suggested classification should allow a clear therapeutic concept. The prognostic value will be analysed in a further study.

Incidence of bladder cancer in a cohort of workers exposed to 4-chloro-o-toluidine while synthesising chlordimeform

Between 1982 and 1990 seven cases of bladder cancer were detected in a group of 49 workers who were synthesising chlordimeform from 4-chloro-o-toluidine. Latency periods ranged from 15 to 23 years. The incidence of bladder tumours in this group was significantly higher than that of the cancer registers of the former GDR, Saarland, and Denmark by factors of 89.7, 53.8, and 35.0 respectively. This provides further evidence that monocyclic aromatic amines such as 4-chloro-o-toluidine may be carcinogenic in humans.

Evaluation of in vivo parameters of drug metabolizing enzyme activity in man after administration of clemastine, phenobarbital or placebo

The 24 h urinary excretion of 6beta-hydroxycortisol and D-glucaric acid, the plasma half lives and total clearances of aminopyrine, and serum gamma-glutamyl-transpeptidase activity have been measured in nineteen healthy male volunteers. The study was done double blind and was conducted as a test of induction of microsomal drug metabolizing enzymes during and after daily doses of 6 mg clemastine, 300 mg phenobarbital or a placebo. The urinary excretion of 6beta-hydroxycortisol and D-glucaric acid was significantly increased in the phenobarbital group, the standard for induction. No changes were observed after treatment with clemastine or placebo. Phenobarbital also reduced the half life of aminopyrine, but it was not affected by clemastine or placebo. Gamma-glutamyl-transpeptidase activity increased only in the phenobarbital group. The elimination constant k2 of aminopyrine and the excretion of glucaric acid in the pre-medication period were correlated (p less than 0.05) The results indicate that the tests were of diagnostic value in determination of microsomal enzyme induction by phenobarbital. Failure to observe similar changes after treatment with clemastine imply failure of induction of this activity under the experimental conditions.