Assessment of the cutaneous immune response during Arthroderma benhamiae and A. vanbreuseghemii infection using an experimental mouse model

BACKGROUND

Dermatophytoses are common but poorly understood skin infections. Most in vivo studies have been performed using the guinea pig as the experimental animal model, which has several limitations.

OBJECTIVES

To develop a mouse model of dermatophytosis suitable for multiple purposes, including the investigation of immunity against dermatophytes.

MATERIALS AND METHODS

Two peculiar fungal species, Arthroderma benhamiae and A. vanbreuseghemii, isolated from tinea in humans having contact with rodents were used for epicutaneous inoculation. During the infection, clinical and histopathological follow-up were performed. The recruitment of immune cells was evaluated by immunofluorescence staining and the levels of cytokine mRNA were quantified by quantitative reverse transcriptase-polymerase chain reaction in the skin of infected mice.

RESULTS

The skin symptoms and microscopic lesions, including the colonization of keratinized epidermal and follicular structures by both dermatophytes, were highly similar to those observed in guinea pig infection models and in natural infections, mimicking acute superficial tinea in humans. The dermal inflammatory cellular infiltrate consisted of macrophages, dendritic cells and especially polymorphonuclear neutrophils, which are one of the histological 'clues' to the diagnosis of dermatophytosis. The in situ cytokine profile was characterized by the overexpression of transforming growth factor-β, interleukin (IL)-1β and IL-6 mRNA during infection, suggesting a role of the T-helper 17 pathway in the establishment of immunity.

CONCLUSIONS

Our new reproducible and validated mouse model of dermatophytosis is a modern in vivo tool that allows a more in-depth understanding of the pathogenesis of human dermatophyte infections.

Increased neuronal nitric oxide synthase dimerisation is involved in rat and human pancreatic beta cell hyperactivity in obesity

AIMS/HYPOTHESIS

Pancreatic beta cell hyperactivity is known to occur in obesity, particularly in insulin-resistant states. Our aim was to investigate whether changes in neuronal nitric oxide synthase (nNOS) function affect beta cell compensation in two relevant models: the Zucker fa/fa rats and pancreatic islets from obese humans.

METHODS

Glucose-induced insulin response was evaluated in the isolated perfused rat pancreas and in human pancreatic islets from obese individuals. Expression of nNOS (also known as NOS1) and subcellular localisation of nNOS were studied by quantitative RT-PCR, immunoblotting, immunofluorescence and electron microscopy.

RESULTS

Pancreatic beta cells from Zucker fa/fa rats and obese individuals were found to be hyper-responsive to glucose. Pharmacological blockade of nNOS was unable to modify beta cell response to glucose in fa/fa rats and in islets from obese individuals, suggesting an abnormal control of insulin secretion by the enzyme. In both cases, nNOS activity in islet cell extracts remained unchanged, despite a drastic increase in nNOS protein and an enhancement in the dimer/monomer ratio, pointing to the presence of high amounts of catalytically inactive enzyme. This relative decrease in activity could be mainly related to increases in islet asymmetric dimethyl-arginine content, an endogenous inhibitor of nNOS activity. In addition, mitochondrial nNOS level was decreased, which contrasts with a strongly increased association with insulin granules.

CONCLUSIONS/INTERPRETATION

Increased nNOS production and dimerisation, together with a relative decrease in catalytic activity and relocalisation, are involved in beta cell hyperactivity in insulin-resistant rats but also in human islets isolated from obese individuals.

Mechanisms of skin adherence and invasion by dermatophytes

Dermatophytes are keratinophilic fungi that can be pathogenic for humans and animals by infecting the stratum corneum, nails, claws or hair. The first infection step consists of adherence of arthroconidia to the stratum corneum. The mechanisms and the kinetics of adherence have been investigated using different in vitro and ex vivo experimental models, most notably showing the role of a secreted serine protease from Microsporum canis in fungal adherence to feline corneocytes. After germination of the arthroconidia, dermatophytes invade keratinised structures that have to be digested into short peptides and amino acids to be assimilated. Although many proteases, including keratinolytic ones, have been characterised, the understanding of dermatophyte invasion mechanisms remains speculative. To date, research on mechanisms of dermatophyte infection focused mainly on both secreted endoproteases and exoproteases, but their precise role in both fungal adherence and skin invasion should be further explored.

[How to read a screening mammography (mammotest)]

The purpose of this chapter is to give to the radiologist some practical information in order to be able to read the mammotests, as they are performed in mass screening for breast cancer in France. The examples shown must help to detect as many small cancers as possible, without inflating the false positive rate. Screening mammotests can be read one by one (first reading), or by large series (second or third reading). To improve both the sensitivity and the specificity, reading technique should be strict, with correct fitting (viewboxes, ambiant light). For each case, a technical evaluation is performed (sharpness, contrast, breast projection), followed by the detection phase (asymmetry, abnormal density or calcifications or distorsion). Then, the image is analyzed (eliminating the typical benign conditions), and finally encoded to formalize the result: normal/suspicious for breast cancer. A good working method and a perfect knowledge of normal and pathologic appearances, allow us to reach the recommended rates for detected cancers and positive tests.

[Preoperative localization of asymptomatic breast lesions by the technique of stereotaxic tattooing and use of a wire. Apropos of 670 cases]

OBJECTIVE

To compare the quality of pre-operative analysis of sub-clinical lesions of the breast using a wire and stereotaxic tattooing.

METHODS

Between 1983 en 1990, 670 cases were analysed. At first needle or wire localisation techniques were used and then from 1988 onwards stereotaxic tattooing, first with the wire technique combined with it and later by itself from 1989 onwards. PLACE STUDY CARRIED OUT: Oscar-lambret Centre in the Department of Surgery and Radiodiagnosis I, BP 307, Lille Cedex.

RESULTS

190 carcinomas were diagnosed (30.7%) of which 20 were micro-invasive and 46 carcinoma in situ. The efficiency of the analysis was evaluated according to the number of explorations that were necessary to remove healthy tissue around the lesion. The wire technique results were significantly different (15.43% = 339 cases), tattooing with wire (9.13% = 144 cases), and tattooing by itself (6.30% = 135 cases).

CONCLUSION

It seems that pre-operative assessment using stereotaxic tattooing is the most reliable of methods because it allows limited excision of the lesion and a more aesthetic approach.

Aminoglutethimide (AG) and hydrocortisone (HC) in bone metastases: a retrospective study

The response rate in bone metastases in 57 patients treated with aminoglutethimide and hydrocortisone was retrospectively assessed. All the X-rays were reviewed by two senior radiologists. A response was observed in 23% of the patients, a stabilization in 32%. The survival was not different whether a response or stabilization was observed. Conversely, survival was significantly worse in patients who experienced a progressive disease.

[Hypopharyngeal cancer in the Northern region and Pas-de-Calais. Epidemiological factors]

Authors report results of two epidemiological studies concerning hypopharynx cancer. The first one is a part of the head and neck cancer registry of Northern France from 1984 to 1987. Hypopharynx tumors represent 18% of the 6019 registered tumors, 99% are squamous cell carcinoma; the annual european standardized incidence rate is 17.0 per 100,000 males and 0.5 per 100,000 females. The second one is a prospective study of 339 hypopharynx cancer patients: 1 out of 3 lives alone and 1 out 3 works at the moment of diagnosis. The average daily tobacco and alcohol consumption are 24 g and 128 g respectively, without any difference regarding professional exposures.

[Clinically localized cancers of the breast. Therapeutic consequences of the evaluation of extension]

The therapeutic modifications induced by pretreatment evaluation were studied in a consecutive series of 852 asymptomatic women with newly diagnosed primary breast cancer attending our center between 1980 and 1984. Staging tests included chest X-rays in 851 patients, bone X-rays in 831, alkaline phosphatase in 826, hepatic enzymes in 818, liver echography in 750 and bone scintigraphy in 504. The intended local treatment was changed for a systemic one in 8 patients due to suspicious abnormalities. The follow-up confirmed evidence of metastases in 6 out of 8 patients (bone: 4; liver: 1; lung: 1). Mastectomy, initially avoided in these 6 patients, was subsequently performed in 2 of them owing to slow progression of distant metastases. On the basis of the current study, pretreatment staging in asymptomatic primary breast cancer cannot be recommended due to the low prevalence of detectable metastases.

Computed tomography of urachal carcinoma

Urachal carcinoma arises in the clinically silent extraperitoneal space between the bladder apex and the umbilicus. Computed tomography was used to correctly diagnose and stage urachal cancer in two patients. In one case a mass was localized to the bladder wall and immediate juxtavesical region; in the other case an advanced locally invasive lesion was seen to engulf and fisulize loops of small bowel and extend through the umbilicus. Urachal carcinoma has a highly characteristic appearance and location on CT images.

[Ulcerated cancers of the breast: results of modified mastectomy. Apropos of 64 cases]

Although, happily, at the present time the actual tendency in mammary neoplastic disease is being increasingly orientated towards conservative treatment, a fairly large number of total mastectomies are still being performed in patients diagnosed at a late stage. The frequency, technical aspects and precise local and general prognosis of this affection are discussed in relation to 63 breast cancers treated surgically between 1975 and 1984. These so-called "trimming" mastectomies represent 4.22% of overall total mastectomies performed during the same period. The surgical technic employed was the Patey type total mastectomy with either primary suturing after-wide separation of borders or closure with a thoraco-epigastric fasciocutaneous flap with internal pedicle. Actuarial survival was satisfactory: 58% at 2 years, 34% at 5 years, survival being significantly better in patients with lack of glandular invasion. This surgical technic should be considered, in combination with other therapy, for these patients, who should not be classed as "unrecoverable".

[Preoperative location of deep subclinical breast lesions using the harpoon technic. Apropos of 149 cases]

Since April 1983, harpoon technique was used for limited excision of subclinical mammography-observed anomalies. The procedure involves the insertion of a harpoon-shaped metallic thread, after detection by mammography, to obtain guidance of surgical procedures. The results of 155 procedures in 149 patients included detection of 38 cancers (26%), confirming documented data in this field.

In vivo sustained release of cisplatin from bioresorbable implants in mice

Two kinds of cisplatin-containing implants were prepared from polylactic acid (type I) and from lactic acid-glycolic acid copolymer (type II). Type I implants were almost unaffected when inserted in the renal parenchyma of mice. In contrast, type II implants evolved clearly after in vivo implantation. X-ray pictures and platinum concentration measurements showed a continuous release of platinum over at least three weeks. The release resulted in high platinum concentrations in the kidney tissues and low plasma concentrations, compared to systemic injection. Type II implants seem adequate for further clinical trials of local treatment by cisplatin.

[The harpoon technic in excision of subclinical mammary lesions. Preliminary results]

Preliminary results are reported of the use of a surgical technique since April 1983 for excision of subclinical mammography-observed anomalies. The procedure involves the insertion of a harpoon-shaped metallic thread, after detection by mammography, to obtain guidance of surgical procedures. Preliminary results in 36 cases included the detection of 10 cancers, confirming documented data in this field, and it would therefore appear worthwhile continuing along this pathway of early diagnosis.

Estradiol and progesterone receptors in breast cancer: prognostic value after relapse

The prognostic significance of estradiol (ER) and progesterone receptors (PgR) for survival from relapse has been studied in two groups of breast cancer patients: group 1, 35 patients in whom receptor levels were measured at the time of mastectomy; group II, 49 patients in whom receptor levels were measured at the time of recurrence. ER+ (greater than 10 fmoles/mg) patients had a better survival from relapse than ER- patients. High levels of PgR (greater than 50 fmoles/mg) had a prognostic significance only in group II patients.