Impact of model perfumes on surfactant and mixed surfactant self-assembly

The impact of some model perfumes on surfactant self-assembly has been investigated, using small-angle neutron scattering. A range of different model perfumes, with differing degrees of hydrophilicity/hydrophobicity, have been explored, and in order of increasing hydrophobicity include phenyl ethanol (PE), rose oxide (RO), limonene (LM), linalool (LL), and dihydrogen mercenol (DHM). The effect of their solubilization on the nonionic surfactant micelles of dodecaethylene monododecyl ether (C12EO12) and on the mixed surfactant aggregates of C12EO12 and the cationic dialkyl chain surfactant dihexadecyl dimethyl ammonium bromide (DHDAB) has been quantified. For PE and LL the effect of their solubilization on the micelle, mixed micelle/lamellar and lamellar regimes of the C12EO12/DHDAB mixtures, has also been determined. For the C12EO12 and mixed DHDAB/C12EO12 micelles PE is solubilized predominantly at the hydrophilic/hydrophobic interface, whereas the more hydrophobic perfumes, from RO to DHM, are solubilized predominantly in the hydrophobic core of the micelles. For the C12EO12 micelles, with increasing perfume concentration, the more hydrophobic perfumes (RO to DHM) promote micellar growth. Relatively modest growth is observed for RO and LM, whereas substantial growth is observed for LL and DHM. In contrast, for the addition of PE the C12EO12 micelles remain as relatively small globular micelles, with no significant growth. For the C12EO12/DHDAB mixed micelles, the pattern of behavior with the addition of perfume is broadly similar, except that the micellar growth with increasing perfume concentration for the more hydrophobic perfumes is less pronounced. In the Lbeta (Lv) region of the DHDAB-rich C12EO12/DHDAB phase diagram, the addition of PE results in a less structured (less rigid) lamellar phase, and ultimately a shift toward a structure more consistent with a sponge or bicontinuous phase. In the mixed L1/Lbeta region of the phase diagram PE induces a slight shift in the coexistence from Lbeta toward L1. The addition of LL to the Lbeta (Lv) region of the DHDAB-rich C12EO12/DHDAB phase diagram also results in a reduction in the lamellar structure (less rigid lamellae), and a shift toward a structure more consistent with a sponge or bicontinuous phase, or a coexisting phase of small vesicles. For the mixed L1/Lbeta region of the phase diagram LL induces a shift toward a greater L beta component.

The Microstructure of Di-alkyl Chain Cationic/Nonionic Surfactant Mixtures: Observation of Coexisting Lamellar and Micellar Phases and Depletion Induced Phase Separation

The evolution of the microstructure and composition occurring in the aqueous solutions of di-alkyl chain cationic/nonionic surfactant mixtures has been studied in detail using small angle neutron scattering, SANS. For all the systems studied we observe an evolution from a predominantly lamellar phase, for solutions rich in di-alkyl chain cationic surfactant, to mixed cationic/nonionic micelles, for solutions rich in the nonionic surfactant. At intermediate solution compositions there is a region of coexistence of lamellar and micellar phases, where the relative amounts change with solution composition. A number of different di-alkyl chain cationic surfactants, DHDAB, 2HT, DHTAC, DHTA methyl sulfate, and DISDA methyl sulfate, and nonionic surfactants, C12E12 and C12E23, are investigated. For these systems the differences in phase behavior is discussed, and for the mixture DHDAB/C12E12 a direct comparison with theoretical predictions of phase behavior is made. It is shown that the phase separation that can occur in these mixed systems is induced by a depletion force arising from the micellar component, and that the size and volume fraction of the micelles are critical factors.

All radial scars/complex sclerosing lesions seen on breast screening mammograms should be excised

AIM

To determine the incidence of pre-malignant and malignant conditions in radial scars identified from screening mammograms in women taking part in the UK NHS breast cancer screening programme.

METHODS

All women in our screening population from 1988 to 2002 with a radiological diagnosis of radial scar or complex sclerosing lesion confirmed on subsequent histopathology were included in this study. Patients were investigated with fine needle aspiration cytology then localisation biopsy (n=46) or straight to localisation biopsy (n=78). Patients where divided into two groups, one with pure RS/CSL with no associated epithelial features and the second with associated ADH, DCIS or invasive cancer.

RESULTS

One hundred and twenty-four lesions were confirmed histologically as radial scar or complex sclerosing lesions. The median age was 58 years. Of the 124 patients, 82 were pure RS/CSL. Forty-two had associated epithelial lesions, 22 patients had ADH and 20 patients had either in situ or invasive carcinoma. Where FNA was performed (n=46), mammograms had shown three lesions suspicious of cancer, which were not proven histologically. Mammograms picked up five malignancies out of the nine RS/CSL with associated cancers. Of these, FNA confirmed malignancy in only two patients. Where FNA was not done (n=78), mammogram had read five pure RS/CSL as cancers. It picked up only four cancers in RS lesions with DCIS/Ca out of 11.

CONCLUSION

All screen-detected stellate lesions should be excised due to their association with pre-malignant and malignant conditions.

Hématome cervical spontané secondaire à une hémorragie extracapsulaire d’un adénome parathyroïdien : à propos de 2 cas

The usual clinical manifestations of a parathyroid adenoma are due, in most of the cases, to hypercalcemia. The development of a spontaneous cervical or cervicomediastinal haematoma is a rare form of presentation. In case of a spontaneous cervical haematoma associated with dysphagia: measurement of serum calcium, phosphate and parathyroid hormone allows the diagnosis of haematoma due to extracapsular haemorrhage from a parathyroid adenoma. We report herein 2 cases.

[Video-assisted parathyroidectomy in the management of patients with primary hyperparathyroidism]

INTRODUCTION

In recent years, different minimally invasive techniques of parathyroidectomy have been described. We performed a retrospective study to evaluate the indications and results of video-assisted parathyroidectomy (Vap) in the management of our patients with primary hyperparathyroidism (PHPT).

MATERIALS AND METHODS

During the last 5 years (1998-2002), we operated on 528 patients with PHPT. Vap was proposed for patients with sporadic PHPT, without associated goiter and without previous neck surgery, in whom a single adenoma was localized by means of sonography and/or sestamibi scanning. Vap was performed by lateral approach with insufflation for patients with adenoma located deeply in the neck and by gasless midline approach for patients with adenoma located anteriorly. A quick parathyroid (qPTH) assay was used during the surgical procedures. Calcemia, phosphoremia and PTH were systematically evaluated in patients on days 1 and 8, 1 month and 1 year after surgery. All patients underwent pre-operative and postoperative investigations of vocal cord movements.

RESULTS

Among 528 patients with PHPT, 228 (43%) were not eligible for Vap: associated nodular goiter (99 cases), previous neck surgery (42 cases), suspicion of multiglandular disease (25 cases), lack of pre-operative localization (48 cases), and miscellaneous causes (14 cases). Vap was performed in 300 patients with sporadic PHPT: 282 lateral access, 17 midline access and 1 thoracoscopy. Median operative time was 50 min (20-130 min). Conversion to conventional parathyroidectomy was required in 42 patients (14%): missed adenomas (11 cases), difficulties of dissection (7 cases), multiglandular disease correctly predicted by qPTH (10 cases); qPTH assay false negative results (3 cases), sestamibi scan false positive results (10 cases) and 1 sonography false positive result. One patient presented definitive recurrent nerve palsy. One patient had a persistent PHPT and one other patient had a recurrent PHPT.

CONCLUSION

Vap can be proposed for more than half of patients with PHPT. In our experience Vap and conventional parathyroidectomy are complementary. Immediate results of Vap are similar to those obtained with conventional parathyroidectomy but no conclusions can be drawn in terms of influence of Vap on the outcome of the patients operated for PHPT.

Identification of patients with a non-recurrent inferior laryngeal nerve by duplex ultrasound of the brachiocephalic artery

A non-recurrent inferior laryngeal nerve (NRILN) is a rare anomaly that may increase the risk of injury during thyroid surgery. A NRILN results from an embryologic developmental abnormality of the aortic arches, demonstrated by the absence of the brachiocephalic artery and the presence of an aberrant subclavian artery (arteria lusoria). In our experience 100% of 104 patients with a NRILN were shown to have these abnormalities. We postulated that duplex scanning of the brachiocephalic artery could identify patients at risk of a NRILN. Twelve patients with an operative diagnosis of a right NRILN and associated vascular abnormalities underwent postoperative duplex scanning of the brachiocephalic artery. The examination was performed using a 7.5 or 3.5 MHz transducer. The average duration of assessment was 5 min. The absence of the brachiocephalic artery and the direct origin of the right common carotid artery from the arch of the aorta were demonstrated in each patient. Duplex scanning is a simple noninvasive method of identifying patients with the arterial abnormalities responsible for a NRILN. This may be used in the preoperative assessment of selected patients.

[Lessons learned from 274 laparoscopic adrenalectomies]

AIMS

To define the role of minimally invasive video-assisted surgery in the surgical management of adrenal disease and discuss the respective indications of the trans and retroperitoneal video assisted approaches.

MATERIALS AND METHODS

During the last 8 years (1994-2001), 330 adrenalectomies were performed in 305 patients: 274 (83%) laparoscopic approaches and 56 (17%) open approach. Open surgery was reserved for patients presenting with large or malignant tumours (29 cases), multiple and/or extraadrenal phaeochromocytomas (13 cases), previous intraabdominal intestinal surgery (10 cases), and in those requiring concomitant intraabdominal surgery (4 cases). Laparoscopic adrenalectomy was performed using the lateral transperitoneal approach for 89 Conn's syndrome, 67 Cushing's syndrome, 2 virilizing tumours, 51 phaeochromocytomas and 65 non secretory tumours greater than 4 cm in diameter. Nineteen patients underwent bilateral adrenalectomy.

RESULTS

There were no deaths. Twenty patients (7.3%) had a complication. Eleven cases required open conversion (4%) because of difficulties with dissection (8 cases), preoperative suspicion of malignancy (2 cases), and one pneumothorax. The average size of tumours was 34 mm (7-110 mm). There were 18 malignant tumours (6.5%): 8 adrenocortical carcinomas, 1 leiomyosarcoma, and 9 metastases. All patients with hormonally secreting tumours were cured of their endocrinopathy. There was 1 death secondary to hepatic metastases in a patient with an adrenocortical carcinoma.

CONCLUSION

Most adrenal tumours are suitable for video assisted excision. The only absolute contraindication is an invasive carcinoma requiring an extended excision. The lateral, transperitoneal approach is the most suitable for tumours greater than 5-6 cm in diameter. Both the transperitoneal or retroperitoneal approaches are suitable for smaller tumours depending on operator choice and experience. However in the presence of a large right lobe of liver or previous intraabdominal surgery the retroperitoneal approach may be preferable.