A comparison of the physical demands associated with various right-angle direct-current power tools.

This work examined the physical demands associated with 4 commercially available direct current right-angle power tools along with their computer controlled fastening strategies. Physical demands were measured via an external instrumented handle that could also control the trigger of each tool. Data revealed that forces recorded by the external handle for each of the 4 tools differed. Independent of Joint-Hardness and Target Torque the Atlas Copco TurboTight® and Cleco Low Torque Reaction fastening strategies, both using a rapid spindle-head rotation strategy, produced the lowest peak and impulse force, respectfully, when compared to the 2 tools that were designed to fasten with a longer duration. This work has shown that short duration fastening strategies provide an ergonomics benefit to the users as it requires less force to operate, such force reduction in previous research has been linked to reduced handle displacement and lower muscle effort.

Physical demands associated with right-angle direct-current power-tools: An evaluation of current technology.

The purpose of this work was to evaluate the physical demands associated with three direct current powered right-angle power tool tightening strategies at various fastener-location-orientations, target torques and joint-hardness. Physical demands were measured using surface electromyography, handle force and upper body kinematics. Results identified TurboTight®, a rapid and short duration fastening strategy, to produce lower handle force impulse, less joint angle displacement, and lower EMG magnitudes when compared to the longer duration fastening strategies tested. The reduced magnitudes associated with TurboTight®, independent of fastener-location-orientations, target torques and joint-hardness, indicate a lower physical demand on power tool operators, providing a significant ergonomic benefit when compared to the slower fastening strategies.

On the mechanism of solid-state phase transitions in molecular crystals - the role of cooperative motion in (quasi)racemic linear amino acids.

During single-crystal-to-single-crystal (SCSC) phase transitions, a polymorph of a compound can transform to a more stable form while remaining in the solid state. By understanding the mechanism of these transitions, strategies can be developed to control this phenomenon. This is particularly important in the pharmaceutical industry, but also relevant for other industries such as the food and agrochemical industries. Although extensive literature exists on SCSC phase transitions in inorganic crystals, it is unclear whether their classications and mechanisms translate to molecular crystals, with weaker interactions and more steric hindrance. A comparitive study of SCSC phase transitions in aliphatic linear-chain amino acid crystals, both racemates and quasi-racemates, is presented. A total of 34 transitions are considered and most are classified according to their structural change during the transition. Transitions without torsional changes show very different characteristics, such as transition temperature, enthalpy and free energy, compared with transitions that involve torsional changes. These differences can be rationalized using classical nucleation theory and in terms of a difference in mechanism; torsional changes occur in a molecule-by-molecule fashion, whereas transitions without torsional changes involve cooperative motion with multiple molecules at the same time.

Inhibition of the Vapor-Mediated Phase Transition of the High Temperature Form of Pyrazinamide.

Tailor-made additives can prove an effective method to prolong the lifetime of metastable forms of pharmaceutical compounds by surface stabilization. Pyrazinamide (PZA) is a pharmaceutical compound with four polymorphic forms. The high temperature γ form, which can be produced by spray drying or sublimation growth, is metastable at room temperature and transforms within days when produced by spray drying, and within several months up to years for single crystals produced by sublimation. However, when PZA is cospray dried with 1,3-dimethylurea (DMU), it has been reported to remain in its γ form for several years. Scanning electron microscopy (SEM) images reveal that the phase transition from γ-PZA to the low temperature forms involves a vapor-mediated recrystallization, while the reverse phase transition upon heating is a nucleation-and-growth solid-solid phase transition. The lifetime-extending effect of DMU on spray-dried PZA has been investigated in more detail and compared with high-energy ball milling of sublimation-grown γ-PZA crystals. Co-ball milling of PZA and DMU is found to extend the lifetime of the high temperature form of PZA to a few months, while separate ball milling leads to an extension of merely a few weeks. DMU acts as an additive that most likely stabilizes the surface of γ-PZA, which would reduce the vapor pressure of PZA, thereby reducing the transition rate. Alternatively, DMU could prevent nucleation of low temperature forms of PZA.

The ex utero intrapartum treatment (EXIT) procedure in fetal neck masses: a case report and review of the literature.

Large fetal neck masses can cause airway obstructions with potential fetal demise after delivery. The relationship of the neck mass to airway structures can be defined prenatally with ultrasound and magnetic resonance imaging (MRI). The ex utero intrapartum treatment (EXIT) procedure can be used to obtain a fetal airway while feto-maternal circulation is preserved to optimise fetal outcome. We present a case in which prenatally a large fetal neck mass was diagnosed on ultrasound and a successful EXIT procedure was performed. A review of the literature is given and the prenatal use of ultrasonography and MRI in case of fetal neck masses is discussed.

The effect of nicotine on DNA repair in adult myocytes.

Recent findings have demonstrated that terminally differentiated adult ventricular myocytes are capable of repairing DNA that has been damaged by exposure to oxygen free radicals. Despite the potential importance of DNA repair in cells that may survive many decades after injury, little is known about the mechanisms or regulation of repair. Since tobacco use has a well-defined role in the epidemiology and pathophysiology of heart disease, we tested the effects of nicotine on repair of free radical damaged plasmids by whole-cell protein extracts from adult myocytes. Exposure to a concentration of 25 microM nicotine increased incorporation of (32P)dCTP into damaged plasmids by 16%, and 50 or 100 microM nicotine increased incorporation by 32%. Nicotine did not alter the rate or amount of poly (ADP-ribose) on the major protein acceptor of molecular weight 113-116 kDa. Inhibition of DNA polymerase activity with pyridoxal 5'-phosphate revealed greater plasmid degradation in the presence of nicotine. We conclude that nicotine enhances DNA degradation and the increased repair is a consequence of this greater degradation.

Rectovaginal septum adenomyotic nodules: a series of 500 cases.

OBJECTIVE: Laparoscopic procedure with excision of deep fibrotic endometriotic nodules of the rectovaginal septum and histological study of the lesions. SETTING: An academic teaching hospital. PARTICIPANTS: A series of 500 women undergoing laparoscopy for pelvic pain or infertility. RESULTS: Laparoscopic (n = 497) and laparotomic (n = 3) excision of endometriotic nodules resulted in considerable pain relief. Histologically the rectovaginal nodule was similar to an adenomyoma as it was a circumscribed nodular aggregate of smooth muscle and endometrial glands and stroma. The variations in oestrogen receptor and progesterone receptor content suggested a regulatory mechanism different from that of eutopic endometrium. CONCLUSION: This form of disease should be considered as an entity distinct from peritoneal and ovarian endometriosis, and originating from the Müllerian rests present in the rectovaginal septum.

Expansive benign lesions: treatment by laser.

Submucous fibroids, polyps and dysfunctional bleeding are responsible for meno-metrorrhagia in women over 40 years of age. The authors describe the technique of hysteroscopic myomectomy and endometrial ablation using the Nd-YAG laser and the advantages of the preoperative use of GnRH agonist therapy. They report their results in a series of 746 patients treated for meno-metrorrhagia (366 cases of myomectomy and 380 cases of endometrial ablation).

Large ovarian endometriomas.

The management of large endometriomas was described in a series of 814 patients. Combined therapy using gonadotrophin-releasing hormone agonist (GnRHa) and carbon dioxide laser laparoscopy was proposed. Drainage and GnRHa for 12 weeks provoked a reduction of the endometrioma size up to 50% of the initial value. After vaporization of the internal wall, a cumulative pregnancy of 51% after 1 year was achieved. A recurrence rate of 8% was observed for a follow-up of 2-11 years. Histological data demonstrated that the epithelium covering the ovary which is the mesothelium can invaginate in the ovarian cortex. Some of the invaginations were seen to be continuous with endometrial tissue, strongly suggesting the metaplasia theory in the pathogenesis of ovarian endometrioma.

Morphometric, immunohistological and three-dimensional evaluation of the endometrium of menopausal women treated by oestrogen and Crinone, a new slow-release vaginal progesterone.

Recently advanced computerized technology was applied to the investigation of morphometric, immunohistological and three-dimensional changes of the endometrial mucosa in order to evaluate quantitatively the effects of three doses of a new slow-release vaginal progesterone on the endometrium in post-menopausal women. A total of 20 menopausal women, deprived of ovarian function, were given oestrogen for 12 days and a combined therapy of oestrogen (administered orally) and progesterone for another 12 day period. Progesterone was administered vaginally through a new gel (Crinone) utilizing a bioadhesive, biocompatible polymer as a base to achieve a sustained release effect. An endometrial biopsy was taken before treatment, after oestrogen-only treatment and after the oestro-progestogen therapy. Before treatment, all the patients exhibited an atrophic endometrium. After oestrogen-only treatment, typical proliferative changes occurred: an increase in the endometrium thickness, an increase in the mitotic index, numerous cylinder-like glands and no coiled glands, and high concentrations of oestrogen receptors (ER) and progesterone receptors (PR). After the oestro-progestogen therapy, whatever the dose of progesterone given, a secretory transformation of the endometrial mucosa occurred, mitotic activity decreased significantly, more ramified and coiled glands were observed, and a decrease in PR content was noted in epithelial and stromal nuclei, and a decrease in PR content was also observed in epithelial nuclei but not in stromal nuclei. Accurate new techniques of image analysis have shown that crinone therapy could eliminate the proliferative effects of oestrogen treatment in post-menopausal women, despite doses as low as 45 mg of progesterone administered vaginally every other day. The results suggest that the sustained release effects of Crinone are clinically relevant.

DNA synthesis in adult feline ventricular myocytes. Comparison of hypoxic and normoxic states.

Adult mammalian ventricular myocytes are terminally differentiated cells, and the prevailing perception has been that DNA synthesis and repair are not active. We tested the hypothesis that there is potential for DNA synthesis and repair by studying the ability of whole-cell extracts from adult myocytes to incorporate [alpha-32P]dCTP into damaged plasmids. Left ventricular myocytes were isolated from adult cat hearts by collagenase dissociation. Cells were maintained in room air (control extract, CE) or made ischemic (IE) with N2 displacement of O2 and extracted for total protein. The nicked form of the plasmid was produced by exposure to an Fe3+/ascorbic acid free radical generating system. Both IE and CE degraded the supercoiled form of the plasmid and incorporated [alpha-32P]dCTP into the nicked (32P/DNA mass; CE = 2.2, IE = 3.0) and linear forms (32P/DNA mass; CE = 28.7, IE = 25.2). Exposure of plasmids to UV light did not inhibit incorporation of label. Inhibition studies with the cell extracts suggested a participation of polymerase delta in myocyte DNA repair/synthesis. Myocyte extract was as active as extract from rapidly growing COS cells at incorporating labeled nucleotides into plasmid DNA. The ability of intact myocytes to incorporate [alpha-32P]dCTP into endogenous DNA was measured in isolated cells made permeable with saponin. Studies were done in room air or N2. Permeable cells incorporated [alpha-32P]dCTP into nuclear DNA, but maximal specific activity of DNA was observed at 15 minutes with ischemia and at 60 minutes with room air control cells (ischemia, 1.34 +/- 0.5, 0.86 +/- 0.33, 0.60 +/- 0.04; air, 1.0, 1.28 +/- 0.20, 1.87 +/- 0.38, at 15, 30, and 60 minutes, respectively). These data indicate that mammalian adult ventricular myocytes can actively repair and/or synthesize both exogenous and endogenous DNA. A DNA synthetic response to cellular damage may have important pathological and clinical implications.

Hysteroscopic myomectomy.

Transhysteroscopic myomectomy has proved to be safe and effective with experienced operators. The use of the continuous flow hysteroscope and preoperative monitoring of intrauterine pressure has contributed to the prevention of fluid intravasion accidents. Effectiveness has been demonstrated in a number of recently published long-term studies.

LASH: laparoscopic supracervical (subtotal) hysterectomy.

From July 1990 to December 1993, 156 laparoscopic supracervical hysterectomies (LASH) were performed. No complications occurred. The technique and the advantages are described. Because of the easy feasibility of this technique, the quick recovery of the patients and the absence of complications this strictly laparoscopic approach must be widely proposed when an hysterectomy is indicated and no risk of remaining cervix cancer is assumed.

Laparoscopic myolysis with the Nd:YAG laser.

Laparoscopic myomectomy can be carried out in cases of subserosal and intramural fibroids. Laparoscopic myolysis can be proposed as an alternative to laparoscopic myomectomy in cases of large or multiple intramural fibroids in women aged over 40 or not desiring to bear more children but wishing to avoid a future hysterectomy. The authors report the technique and the long-term results in a series of 48 women with fibroids treated by myolysis. Because of the risk of bowel adhesions, further studies with another type of laser fiber are required.

[Correlations between delayed auditory evoked potentials and clinical evaluation of schizophrenic symptoms]. / Corrélations entre les potentiels évoqués auditifs tardifs et l'évaluation clinique des symptômes de schizophrénie.

Late auditory evoked potentials (AEPs) were recorded by the "odd-ball" method in 20 schizophrenic patients according to DSM III R diagnosis criteria compared with 30 control subjects matched for sex and age. Patients were on antipsychotic medications; mean duration of illness was 3, 55 years. We have also proceeded to a clinical quantitative assessment of negative and positive symptoms of schizophrenia with Andreasen's rating scales. In the group of patients, we have observed a significant lengthening of the latency of N 1, N 2, P 3, N 3 and a decreased amplitude of N 1 and P 3. These results are in favour of an impairment of cerebral information processing probably localized in the subcortical level. Statistically significant correlations have been noticed between the anomalies of the last stages of information processing (P 3, N 3) and negative symptoms, more particularly affective flattening and attentional impairment. The disturbances of the first stages of information processing (P 2) and of automatic information processing (N 2) were related to positive symptoms, hallucinations and delusions especially. The anomalies of N 2 were also related to the sum of the global scores: an attentional impairment could be a main factor in the determinism of schizophrenia.