Dry-compression packing of hydroxyapatite nanoparticles within a flat cuboid chromatography device and its use for fast protein separation.

We describe and discuss a simple dry-compression technique for preparing a flat cuboid chromatography device containing a shallow packed-bed of crystalline hydroxyapatite nanoparticles. We then discuss the use of this device for fast protein separation in the bind-and-elute mode. Such separation could be carried out at quite low pressures, making it possible to use inexpensive low pressure chromatography systems. In the flow rate range examined in this study, the pressure-drop across the device increased linearly with flow rate, indicating negligible media compaction during use. Using this device, binary protein mixtures could be separated in about a minute. Contrary to that observed in most packed-bed chromatographic separations, the width of the flow through and eluted peaks decreased with increase in flow rate. Therefore, both productivity and purity could be simultaneously increased by increasing flow rate. The suitability of this device for preparative protein separations was demonstrated by carrying out purification of a monoclonal antibody (Trastuzumab) from mammalian cell culture supernatant. This study opens up the possibility of developing dry-compression based flat cuboid packed-bed chromatography devices for fast preparative protein separation.

Catalogue of the Diptera (Insecta) of Morocco- an annotated checklist, with distributions and a bibliography.

The faunistic knowledge of the Diptera of Morocco recorded from 1787 to 2021 is summarized and updated in this first catalogue of Moroccan Diptera species. A total of 3057 species, classified into 948 genera and 93 families (21 Nematocera and 72 Brachycera), are listed. Taxa (superfamily, family, genus and species) have been updated according to current interpretations, based on reviews in the literature, the expertise of authors and contributors, and recently conducted fieldwork. Data to compile this catalogue were primarily gathered from the literature. In total, 1225 references were consulted and some information was also obtained from online databases. Each family was reviewed and the checklist updated by the respective taxon expert(s), including the number of species that can be expected for that family in Morocco. For each valid species, synonyms known to have been used for published records from Morocco are listed under the currently accepted name. Where available, distribution within Morocco is also included. One new combination is proposed: Assuaniamelanoleuca (Séguy, 1941), comb. nov. (Chloropidae).

A checklist of the Diptera (Insecta) of the Maltese Islands.

A checklist is presented of all 986 extant species of Diptera known from the archipelago of the Maltese Islands situated in the central Mediterranean. Species considered to be alien to the Islands are listed with annotations in Appendix 1. The history of dipterology applicable to the islands is outlined and the three important historical published records by Zetterstedt, Rondani and Bezzi de Stefani-Perez are listed in Appendices 24. Species names that are synonyms are indicated where these were used in published records for Malta more or less after the Catalogue of Palaearctic Diptera was published. Species we consider to have been misidentifications are also indicated with an annotation in most cases. Vermileo immaculatus Carles-Tolr syn. n. Cuesta-Segura and Vermileo balearicus Wheeler syn. n. are proposed junior synonyms of Vermileo vermileo (Linnaeus).

A flow distribution and collection feature for ensuring scalable uniform flow in a chromatography device.

We discuss how the efficiency of a chromatography device could be enhanced by incorporating a new feature which ensures flow uniformity. The overall flow of fluid within the device, which has a cuboid shape, could be visualized as a combination of two z patterns. The device is therefore designated as cuboid z2. The reason for flow uniformity is explained using a simple mathematical model, and also based on computational fluid dynamic (CFD) simulations. The cuboid z2 device outperformed its equivalent conventional cylindrical column in terms of separation efficiency metrics such as the number of theoretical plates, the reduced plate height, and attributes of non-interacting tracer solute peaks. The results discussed in this paper clearly indicate the suitability of the cuboid z2 device for carrying out high-resolution chromatographic separations. The z2 flow enhancing feature would also be broadly applicable to any process which requires uniform flow in three-dimensional porous media. In addition to superior fluidic attributes, the cuboid z2 chromatography device has other advantages such as compactness and scalability.

A z2 laterally-fed membrane chromatography device for fast high-resolution purification of biopharmaceuticals.

We examine the use of a z2 flow distribution and collection feature for enhancing the separation efficiency of a laterally-fed membrane chromatography (or LFMC) device. The new device is designated z2LFMC. Two devices were fabricated using two different ion-exchange membranes: strong anion exchange (Q) with 0.8-micron pore size, and strong cation exchange (S) with pore size in the 3-5 µm range. The number of theoretical plates per unit membrane bed height in these z2LFMC devices were higher than those reported for other membrane chromatography devices housing similar membranes, including the older versions of LFMC devices. The enhancement in separation efficiency is explained based on computational fluid dynamic (CFD) simulations. Model protein separation experiments showed that the z2LFMC device gave similar resolution as an equivalent resin-packed column, at 40-time greater flow rate than that used with the column. At a comparable flow rate, the resolution obtained with the z2LFMC device was significantly higher than that obtained with the equivalent resin-packed column. Therefore, the z2LFMC device combines high-speed with high-resolution. We demonstrate the suitability of the z2LFMC devices for carrying out fast and efficient biopharmaceutical separations through two case studies, i.e. the fractionation of monoclonal antibody charge variants, and monoclonal antibody aggregates separation.

Can leprosy be eradicated with chemotherapy? An evaluation of the Malta Leprosy Eradication Project.

The Malta Leprosy Eradication Project (MLEP) was proposed in 1971 by Freerksen with the aim of eradicating leprosy in Malta. The project involved re-treatment of all known cases in Malta as of 1972 and all new cases thereafter with a regimen consisting of Isoprodian (a combination of dapsone, prothionamide and isoniazid) and rifampicin for varying intervals depending on the severity of their disease and their response to treatment. Overall the response to therapy was excellent with an extremely low relapse rate. During the 30 years of the project the incidence of leprosy steadily decreased continuing a decline that had started at least two decades earlier and Freerksen declared the disease eradicated from Malta in 2001. Although given the long incubation period of leprosy cases may still be occasionally detected in the future, the disease has been basically eradicated at this time and there are no patients currently receiving treatment. This work was done at the leprosy clinic, Boffa Hospital, Floriana, Malta.

Cutaneous melanoma in the Maltese Islands: 2000-2004.

This study aimed to, prospectively, over the 5-year period 2000-2004, accurately determine features of cutaneous melanoma in the Maltese Islands. Data from clinicians were supplemented by histology reports, and where necessary, histology slides were reviewed. Information collected included demographic details including age and gender, anatomical site, Clark's level, Breslow thickness and clinico-pathological melanoma type. During the study period the age-standardised (European Standard Population) rates for invasive melanoma were 8.81 per 100,000 (males) and 7.29 per 100,000 (females) and increased with age. By the end of the study, information on 166 cases of primary invasive cutaneous malignant melanoma were collected. The commonest site affected in males was the trunk (54%) and in females the lower limbs (41%). Overall, 33.8% of invasive melanomas had a Breslow thickness >1.5mm. The initial melanoma excision was performed by a dermatologist in 68.2% and plastic surgeon in 20.8%. More cases presented in late spring and summer, particularly in females. Melanoma incidence in Malta is lower than that in high-incidence countries and northern Europe and is similar to that in southern Europe. However, incidence appears to be increasing and a relatively high proportion of patients present with thick lesions emphasising the importance of continued efforts to diagnose cases earlier.

Nasal polyps: a predisposing factor for cutaneous leishmaniasis of the lips?

OBJECTIVES: Cutaneous leishmaniasis (CL) of the lips is rare. This study was conducted to investigate findings in patients with this condition. METHODS: From 2007 to date, we observed 10 patients (nine males and one female), with a median age of 45.2 years (range: 8-77 years), with CL of the lips. RESULTS: Six of the 10 patients suffered from nasal polyps, three from bronchial asthma, and one from chronic obstructive pulmonary disease (COPD). Three of the patients with nasal polyps also had asthma. Three patients had none of nasal polyps, asthma, or COPD. In all patients with nasal polyps, diagnosis was confirmed by anterior rhinoscopy and nasal endoscopy. CONCLUSIONS: It is possible that, in patients with nasal polyps, asthma, and COPD, the need to breathe through the mouth rather than the nose facilitates the sting by sandflies. Subjects with nasal polyps living in areas endemic for CL should be warned about the risk for being stung by sandflies on the lips, in addition to other uncovered areas.

Characteristics of superficial mycoses in Malta.

BACKGROUND: A study was conducted to determine the chief agents of superficial mycoses in Malta. Data were collected over a 5-year period from mycologic investigations carried out on all dermatologic specimens sent to the Mycology Laboratory at St. Luke's Hospital in Malta. METHODS: In the period between January 1995 and December 1999, a total of 1271 specimens from skin, nails, or hair were collected from 1200 clinically suspected cases of dermatomycoses. RESULTS: The fungi cultivated included dermatophytes (n = 371), yeasts (n = 33), and nondermatophyte filamentous fungi (n = 12). Trichophyton rubrum (n = 121) was the most prevalent, followed by Microsporum canis (n = 109), T. mentagrophytes (n = 80), M. gypseum (n = 27), Epidermophyton floccosum (n = 17), T. soudanense (n = 10), T. tonsurans (n = 2), T. verrucosum (n = 2), M. persicolor (n = 1), and T. violaceum (n = 1). Candida species were also cultivated, with C. parapsilosis (n = 14) being the most common, followed by C. albicans (n = 12) and C. tropicalis (n = 6). Nondermatophyte filamentous fungi were isolated from nail specimens only. CONCLUSIONS: In this study, superficial fungal infections were reported more commonly in female (n = 207) than in male (n = 182) patients. M. canis was the chief agent of tinea capitis and tinea corporis, whilst T. rubrum was the main causative agent of tinea pedis, tinea manuum, and tinea unguium. Onychomycosis due to Candida species was more common in female than in male patients.