Cell division angle predicts the level of tissue mechanics that tune the amount of cerebellar folding

Modeling has led to proposals that the amount of neural tissue folding is set by the level of differential expansion between tissue layers and that the wavelength is set by the thickness of the outer layer. Here, we used inbred mouse strains with distinct amounts of cerebellar folding to investigate these predictions. We identified a distinct critical period during which the folding amount diverges between the two strains. In this period, regional changes in the level of differential expansion between the external granule layer (EGL) and underlying core correlate with the folding amount in each strain. Additionally, the thickness of the EGL varies regionally during the critical period alongside corresponding changes in wavelength. The number of SHH-expressing Purkinje cells predicts the folding amount, but the proliferation rate in the EGL is the same between the strains. However, regional changes in the cell division angle within the EGL predicts both the tangential expansion and the thickness of the EGL. Cell division angle is likely a tunable mechanism whereby both the level of differential expansion along the perimeter and the thickness of the EGL are regionally tuned to set the amount and wavelength of folding.

Cell division angle regulates the tissue mechanics and tunes the amount of cerebellar folding

Modeling has proposed that the amount of neural tissue folding is set by the level of differential-expansion between tissue layers and that the wavelength is set by the thickness of the outer layer. Here we used inbred mouse strains with distinct amounts of cerebellar folding to investigate these predictions. We identified a critical period where the folding amount diverges between the strains. In this period, regional changes in the level of differential-expansion between the external granule layer (EGL) and underlying core correlate with the folding amount in each strain. Additionally, the thickness of the EGL is regionally adjusted during the critical period alongside corresponding changes in wavelength. While the number of SHH-expressing Purkinje cells predicts the folding amount, the proliferation rate in the EGL is the same between the strains. However, regional changes in the cell division angle within the EGL predicts both the tangential-expansion and thickness of the EGL. Cell division angle is likely a tunable mechanism whereby both the level of differential-expansion and thickness of the EGL are regionally tuned to set the amount and wavelength of folding.

Evaluation of interstitial diode laser therapy for treatment of benign prostatic hyperplasia

In the last decade, a number of new device technologies were developed for benign prostatic hyperplasia (BPH) therapy. These technologies were introduced in an effort to reduce the morbidity of BPH therapy associated with conventional electrocautery transurethral resection of the prostate (TURP). While morbidity is reduced, the aim of new therapy is to achieve near equivalence in efficacy of outcome measures, namely, improved voided flow rate and reduced symptom score. To gain acceptance by urologists, these technologies should be easy to apply and should reduce the economic cost of BPH treatment. The Indigo 830e diode laser system offers simplified laser therapy from a miniaturized solid-state system. This pilot study demonstrates outcome equivalence to TURP in preliminary evaluation and shows an acceptable side effect profile.

A randomised single institution study comparing laser prostatectomy and transurethral resection of the prostate

We concluded a prospective randomised study comparing conventional electrocautery transurethral resection of the prostate (TURP) to laser prostatectomy using a right-angled Nd:YAG beam reflector. Seventy-one patients were evaluable, 34 laser and 37 TURP. Fifty patients have completed 6 months of follow-up. Using standard post prostatectomy outcome parameters of maximum flow rate and post void residual urine, laser prostatectomy shows equivalence at 6 months, with mean maximum flow rates of 8.76 ml/sec preoperatively improving to 15.47 ml/sec at 6 months, whilst for TURP patients, flow rates improved from a mean of 9.48 ml/sec preoperatively to 19.1 ml/sec at 6 months. Symptom scores remain higher for the laser patients at this time with a mean score of 9.27 compared to 4.43 for TURP patients. However, morbidity in the laser group is less, particularly given the absence of postoperative bleeding and the necessity for blood transfusion.

Noncontact sidefire laser ablation of the prostate

Continuing experience with Nd:YAG noncontact sidefiring laser fibers over the past 4 years has shown encouraging results. Thus far, of the 198 patients treated with the 60 W/60 seconds technique since October 1990, a total of 74 were available for long-term evaluation (69 at 12 months and 29 at 24 months). The AUA Symptom Scores, Qmax (peak uroflow rates), and postvoiding residual urine volumes demonstrated marked improvement. The complications included 16 instances of recurrent obstructive symptoms necessitating revision. Three patients suffered urinary tract infections, two patients developed bladder neck stenosis, four anticoagulated patients with clot retention required blood transfusions, and three patients had epididymoorchitis. Follow-up at 12 and 24 months showed sustained reduction in AUA Symptom Scores and maintained improvement of the peak flow rates and residual volumes. These results demonstrate the safety and clinical applicability of laser ablation of the prostate and its potential usefulness as a less invasive therapy for benign hyperplasia.

Transurethral laser ablation of the prostate--long-term results

Continuing experience with the use of Nd:YAG laser-fibre prostatectomy over the past 4 years has produced encouraging results. Of the 198 patients we treated with the 60-W/60-s technique, 74 were available for evaluation after undergoing laser ablation of the prostate between October 1990 and July 1994. In all, 29/74 and 9/74 patients were available for 24 and 36 months of follow-up, respectively. The American Urological Association (AUA) symptom scores, peak uroflow (Qmax) rates and post-void residual urinary volumes show marked improvement. Following laser ablation of the prostate (LAP), complications have included 16 patients with post-procedural recurrent obstructive symptoms requiring revision. Three patients developed urinary tract infection, two developed bladder-neck stenosis, four fully anticoagulated patients with clot retention required blood transfusion and three patients had epididymo-orchitis. The results show a sustained reduction in AUA symptom scores and maintained improvement in peak flow rates and residual volumes, with stabilization of the above-mentioned parameters occurring within 12-36 months. The results demonstrate the continued durability of the outcome of LAP.

Second-generation delivery systems for laser prostatic ablation

OBJECTIVE

To assess the effectiveness of a second-generation laser delivery system (Side-Fire) in the treatment of benign prostatic hyperplasia (BPH).

METHODS

Thirty-three patients with documented BPH were treated and evaluated pre- and post-operatively with a follow-up period of twelve to thirty-six weeks.

RESULTS

There was marked improvement demonstrated at three months post lasing in all patient outcome parameters (symptom score, flow rate, and post-void residual volume) using the new Side-Fire right-angled delivery system.

CONCLUSION

Side-Fire catheter laser ablation therapy produces an excellent transition zone ablation in established BPH.

Simple automatic initiator for microwave induced plasmas

A simple circuit is described which is used to maintain continuity of a radio-frequency or microwave induced plasma. The microwave power reflected from the discharge is monitored. Upon an increase of the reflected power which indicates that the plasma has become extinguished, a high-voltage pulse is applied to a coil wrapped around the discharge region. The repetition rate, voltage of the pulse, and threshold of reflected power are adjustible. This circuit is applicable to resonance fluorescence, atomic absorption and emission, and kinetic determinations.