Primary malignant CNS lymphoma in an immunocompetent patient: A case report

Aim and Objective: Primary malignant CNS lymphoma in otherwise healthy immunocompetent subject is relatively uncommon.They occur more frequently in immunocompromised patients. In this case report, we presented a report of an immunocompetent 48 year old male with primary CNS lymphoma.Clinical presentation: A 48 year old male was admitted in the neurosurgery department of Apollo hospital Dhaka because of continuous headache and vomiting for 15 days. There was no history of any illness, medication or head trauma. He was tested negative for HIV test. MRI revealed a periventricular mass which was confirmed as primary CNS lymphoma, diffuse large cell type by histopathology and immunohistochemical examination.Conclusion: We presented this case because of relatively uncommon occurrence and raising incidence of primary CNS lymphoma in immunocompetent subjects in last one or two decades.DOI: http://dx.doi.org/10.3329/pulse.v4i1.6960Pulse Vol.4 January 2010 p.26-27

Primary amelanotic anorectal melanoma: an uncommon neoplasia with poor prognosis

BACKGROUND

Anorectal melanoma is a rare and aggressive mucosal cancer. There is usually a delay in diagnosis because about 30% of these cancers are amelanotic and are often mistaken for benign conditions. Herein, we report a case of amelanotic anorectal malignant melanoma with an unusual metastatic deposit in the vulva and also review the literature.

CASE REPORT

A 67-year-old woman presented with a history of prolapse of an anal tumour. Clinical examination showed a pedunculated and ulcerated amelanotic tumour associated with three other nodules, 1 cm in diameter, localized in the vulval mucosa. A left inguinal node was palpable. Histological examination and immunohistochemical staining of all tumours demonstrated malignant melanoma. Radiological diagnostic procedures revealed no evidence of metastases.

DISCUSSION

Nine cases of amelanotic malignant melanoma have been reported in the literature. The age at diagnosis ranged from 45 to 77 years. Females appear to be far more frequently involved than males (F/M = 7/2). Anorectal melanoma is most common in the rectum, followed by the anal canal. Metastases occur early. Our case is the tenth case of amelanotic anorectal melanoma and probably corresponds to multiple synchronous primary melanomas of the anorectal region and the vulva, with the possibility that one of the lesions is a primary melanoma and the others are satellite lesions. Wide local excision where negative margins can be achieved is the preferred treatment.

Primary cutaneous marginal zone B-cell lymphoma: clinical and histological aspects

According to the WHO-EORTC classification of cutaneous lymphomas, primary cutaneous marginal zone B-cell lymphoma are now well characterized. We report here a case of primary cutaneous marginal zone B-cell lymphoma in a 51 year-old man in which the diagnosis was made using both histology and immunopathology. The patient had no remarkable medical history, no history of either acute inflammation or insect bite, and presented with a 5 cm solitary asymptomatic erythematous firm, multinodular and infiltrated plaque on the back for 12 months. Histological examination and immunohistochemical study of a cutaneous biopsy provided a differential diagnosis between B cell lymphoma and lymphocytoma cutis. Full body work up revealed no signs of extracutaneous dissemination. The patient underwent surgical excision of the nodule. Histological examination showed a histological and immunophenotyping profile typical of primary cutaneous marginal zone B-cell lymphoma. The lesion was completely excised with clear margins and no recurrence occurred after a 12 month-follow-up period. Primary cutaneous marginal zone B-cell lymphoma are low-grade lymphomas that have an indolent course and a high tendency to recur. They should be differentiated from lymphocytoma cutis and from the other types of cutaneous B cell lymphomas that have a different course and prognosis.

[Fast installation of blepharochalasis]

Blepharochalasis is characterized by recurrent painless oedema of the eyelids leading to alteration of periorbital skin with a nearly complete loss of elastic fibers. It usually affects the upper eyelids bilaterally. An 11-year-old girl suffered from recurrent erythematous swelling episodes during 3 months. The manifestations were confined to the periorbital region. She gradually noticed a bilateral loss of elasticity of the skin of the upper eyelid. The skin showed some folding and laxity. A mild aponeurotic ptosis was present. A skin biopsy showed the absence of elastic fibres. Blepharochalasis is a disease of young people. It has been divided in two hypertrophic and atrophic types. The condition typically follows recurrent painless episodes of oedema infiltrating both upper eyelids. The eyelid oedema usually resolves after several days and recures several times a year.

Granuloma annulare

AIM

Granuloma annulare (GA) is a palisading granulomatous skin disease. It is a relatively common dermatosis typically characterized by an annular arrangement of erythematous or flesh-coloured papules. The aim of this study was to assess the epidemiological and clinical pattern of GA and its management.

METHODS

A retrospective study dealing with 35 cases of GA collected during an 11-year period from 1995 to 2005 was carried out at the Dermatology Department of Charles Nicolle's Hospital of Tunis.

RESULTS

There were 24 females and 11 males including 13 children. Four clinical patterns were observed: localized GA with annular shaped lesions in 22 cases (62.8%), subcutaneous GA in 9 cases (25.7%) with 4 children, combination of localized and subcutaneous patterns in one child (2.8%), generalized GA in one adult-patient (2.8%) and combination of generalized and subcutaneous patterns in 2 cases (5.7%). Associated diabetes mellitus was seen in 9 adults (25%) and thyroid diseases in 2 other adults (5.7%). Topical steroids were proposed in 9 cases with partial resolution in 6 of them. Four patients were treated by hydroxychloroquine with an improvement in 3 of them. Two patients (generalized GA with subcutaneous form and subcutaneous GA) were treated by dapsone with partial clearing.

CONCLUSION

In these series, GA has the same epidemiological and clinical pattern as other series of the literature. Subcutaneous form had a pseudo-rheumatoid presentation in adults and an exclusive involvement of children when it is localized on the scalp. Associated systemic diseases, especially diabetes mellitus, are frequent in the series here observed.

Primary umbilical endometriosis: a rare variant of extragenital endometriosis

Endometriosis is defined as the presence of extra-uterine endometrial tissue. The prevalence rate of umbilical endometriosis ranges from 0.5 to 1.0% of all patients with extragenital endometriosis. In this report, we present a case of primary umbilical endometriosis to highlight the challenges encountered during diagnosis. A nulliparous 39-year-old woman presented to our department with a 2-year history of a tender, painful and non-reducible, firm umbilical mass that enlarged slowly reaching 2 cm in diameter. She had never been pregnant nor had any abdominal surgery. There was no sequential bleeding. Ultrasound of the umbilical region showed a well defined, oval shaped anechoic area. Histological examination on a cutaneous biopsy concluded umbilical endometriosis. The patient was subsequently referred to a gynecologist and underwent surgery with en bloc excision of the lesion. Generally, umbilical endometriosis presents as a roundish tumuor that can either partly or completely occupy the umbilical scar with intermittent bleeding. Characteristically, the mass increases with the menstrual cycle, becoming more evident and usually harder and is associated with cyclic pain. Its pathogenesis remains uncertain. Clinical diagnosis is difficult, and umbilical endometriosis can be easily confused with other conditions such as benign and malignant tumours. Ultrasound examination is useful, and surgical excision is the treatment of choice. Several cases of malignant transformation have also been described.

Cutaneous sarcoidosis in Tunisia

AIM

Sarcoidosis is a multisystem disease of unknown etiology characterized by granulomatous infiltration. As clinical features vary among patients from different ethnic groups and geographic areas, local reports are of great interest. The aim of this study was to make an inventory of the clinical presentation of cutaneous sarcoidosis in Tunisia.

METHODS

The study was conducted in an academic teaching hospital, inpatient and outpatient department. The authors retrospectively reviewed the medical records of all patients diagnosed with sarcoidosis at the Dermatological Departement of Charles Nicolle teaching Hospital, Tunis, within a 32-year period.

RESULTS

One hundred and eighteen patients were diagnosed to have sarcoidosis, corresponding to 25 males and 93 females. Mean age at presentation was 39.5 years. Childhood sarcoidosis represented 14.4% of cases. Cutaneous involvement was dominated by micronodular lesions. Chest X-rays abnormalities were present in 28 patient/93 (30.1%). Most of them were at stage 1 or 2. Peripheral lymph node enlargement was reported in 15 patients (12.7%). Other internal organ involvements corresponded to: eyes (15 cases); bones (12 cases), joints (5 cases), gasto-intestinal tract (5 cases), upper airways (5 cases), liver (4 cases), kidney ( 1 case) and muscles (1 case). Systemic involvement was noticed in 88% patients with lupus pernio. Treatment modalities included topical and oral corticosteroids, hydroxychloroquine, allopurinol and surgical excision with variables outcomes.

CONCLUSION

The data of this study suggest that sarcoidosis manifests with a wide range of cutaneous lesions in Tunisian patients and that extracutaneous involvement is not rare. Remarkable clinico-epidemiological characteristics are the clear predominance in women, the high frequency of childhood cases and the predominance of micronodular skin lesions.

Serum and forskolin cooperate to promote G1 progression in Schwann cells by differentially regulating cyclin D1, cyclin E1, and p27Kip expression

Proliferation of Schwann cells in vitro, unlike most mammalian cells, is not induced by serum alone but additionally requires cAMP elevation and mitogenic stimulation. How these agents cooperate to promote progression through the G1 phase of the cell cycle is unclear. We studied the integrative effects of these compounds on receptor-mediated signaling pathways and regulators of G1 progression. We show that serum alone induces strong cyclical expression of cyclin D1 and E1, 6 and 12 h after addition, respectively. Serum also promotes strong but transient erbB2, ERK, and Akt phosphorylation, but Schwann cells remain arrested in G1 due to high levels of the inhibitor, p27(Kip). Forskolin with serum promotes G1 progression in 22% of Schwann cells between 18 and 24 h by inducing a steady decline in p27(Kip) levels that reaches a nadir at 12 h coinciding with peak cyclin E1 expression. Forskolin also delays neuregulin-induced loss of erbB2 receptors allowing strong acute activation of PI3K, sustained erbB2 phosphorylation and G1 progression in 31% of Schwann cells. We find that the ability of forskolin to decrease p27(Kip) is associated with its ability to decrease Krox-20 expression that is induced by serum and further increased by neuregulin. Our results explain why serum is required but insufficient to stimulate proliferation and identify two routes by which forskolin promotes proliferation in the presence of serum and neuregulin. These findings provide insights into how G1 progression and, cell cycle arrest leading to myelination are regulated in Schwann cells.

Tinea faciei: a report on four cases

Four cases of tinea faciei that were observed at the Department of Dermatology of Charles Nicolle Hospital in Tunis are reported. All patients were females, ages 54 (patient 1), 38 (patient 2), 30 (patient 3), and 50 (patient 4). The lesions lasted 1 year, 2 months, 4 months, and 1 month, respectively. Tinea faciei was initially suspected in three patients, whereas for the second patient eczema was initially suspected. She was first treated topically with corticosteroids leading to exacerbation. Through mycological examination, Trichophyton rubrum was isolated in three patients, but was negative in patient 2. Three patients recovered completely after one month of griseofulvin associated with topical terbinafine. Patient 3 was topically treated because she was pregnant. Erythematous lesions of the face must be checked for fungi.

[Kindler syndrome: three cases reports in three siblings]

INTRODUCTION

Kindler syndrome is a rare type of genetic skin condition belonging to the class of bullous poikilodermia. We report three new cases of this rare syndrome.

CASE REPORTS

This condition was seen in two brothers aged 4 and 14 years and in their sister aged 6 years, born of a first-degree consanguineous marriage in a family with Kindler syndrome of varying degrees of severity. The three patients presented spontaneously regressive bullous eruptions, poikilodermia of gradual onset, major cutaneous atrophy on the back of the hands and the feet, pseudo-syndactyly and photosensitivity. The older brother presented a severe form complicated by chronic terminal renal failure with hydronephrosis secondary to urethral stenosis and hypertension as well as oesophageal stenosis requiring dilatation sessions. Electron microscopy examination of poikilodermic skin showed normal anchoring filaments and proliferation of the basal layer. Electron microscopy examination of rubbed poikilodermic skin from the other two siblings showed cleavage at both the superficial and deep intra-epidermal levels.

DISCUSSION

Diagnosis of Kindler syndrome is based upon clinical evidence. Electron microscopic examination is used in particular to rule out congenital bullous epidermolysis. Detachment of layers at two or three different levels in relation to the dermal-epidermal junction described in the literature forms a specific but inconsistent feature of Kindler syndrome.

Granuloma faciale

Granuloma faciale is a rare, benign skin condition that usually occurs on the face. Using an exemplary case of granuloma faciale, we will present the clinical and histological characteristics of this dermatosis. A 49-year-old man presented with a 6-month history of a 10 mm-diameter asymptomatic papulo-nodular red-brown lesion of the nose. A biopsy specimen led to the diagnosis of granuloma faciale. The patient received a session of pulsed-dye laser therapy, which led to significant improvement. This benign and usually isolated dermatosis can more rarely be extrafacial. It may often be mistaken for other benign dermatoses (sarcoidosis, discoid lupus erythematosus) as well as for malignant dermatoses (lymphoma, basal cell carcinoma). Histology is

Cytokines Maintain Lymphocyte Homeostasis through the Activity of Cdc25A (B56)

Homeostasis of the peripheral immune system is maintained through signals transduced by cytokines like interleukin-7 (IL-7). In the absence of IL-7 cells undergo apoptosis, while excess IL-7 leads to proliferation. The mechanisms by which IL-7 regulates these processes are poorly understood. We observed that expressing an anti-apoptotic protein (BCL-2) or inhibiting a pro-apoptotic protein (BAX) prevented cell death but did not support growth. Using cytokine-dependent lymphocytes, we found that the G1-to-S phase progression was not solely dependent on the synthesis of cyclin dependent kinases (cdks) and cyclins or the inactivation of inhibitors. Rather it was the removal of inhibitory phosphorylations on cdks by a phosphatase, Cdc25A, which primarily transduced cytokine-mediated growth signals. Cytokine deprivation lead to cell cycle arrest by inducing the activity of p38 MAPK, which destabilized Cdc25A. Inhibiting p38 or expressing a mutant Cdc25A, in which p38 target sites were mutated, promoted cell cycling independent of a cytokine signal. Cells expressing the Cdc25A mutant, in the absence of cytokines, actively synthesized DNA, expressed hyperphosphorylated Rb protein, maintained glucose uptake and did not undergo apoptosis, even in the presence of p27. Cdc25A is a novel transducer of cytokine-mediated growth signals and regulation of its activity is a means by which IL-7 controls proliferation.

International grading scheme for acute rejection in small bowel transplantation: implementation and experience at the University of Miami

In 2003, an international collection of pathologists and clinicians proposed a unified grading system for acute cellular rejection in endoscopically derived small intestine allograft biopsies. This grading system was implemented at the University of Miami over the past 2 years and the results are presented herein. A total of 1136 small bowel allograft biopsies with sufficient tissue for analysis were obtained from 123 hospitalized, clinic, and referral patients. The overall most common diagnosis assessing all time periods was grade IND (40%), and grade 1 rejection or greater was present in 19% percent of biopsies. A suspected vascular component to the acute rejection as identified by specific mucosal vascular changes was present in 6% of cases. Clinical decision making was very consistent with different grades. Our experience has confirmed that this new grading system is reliable and identifies clinical subsets of patients that can receive different therapy. We recommend that this international grading system be implemented for acute cellular rejection in bowel allografts as a means to standardize pathological assessment of alloimmune-induced graft injury, which will allow comparisons between different centers and clinical trials.

Resveratrol inhibits Src and Stat3 signaling and induces the apoptosis of malignant cells containing activated Stat3 protein

Resveratrol is a naturally occurring phytoalexin with antioxidant and antiinflammatory properties. Recent studies suggest that resveratrol possesses anticancer effects, although its mechanism of action is not well understood. We now show that resveratrol inhibits Src tyrosine kinase activity and thereby blocks constitutive signal transducer and activator of transcription 3 (Stat3) protein activation in malignant cells. Analyses of resveratrol-treated malignant cells harboring constitutively-active Stat3 reveal irreversible cell cycle arrest of v-Src-transformed mouse fibroblasts (NIH3T3/v-Src), human breast (MDA-MB-231), pancreatic (Panc-1), and prostate carcinoma (DU145) cell lines at the G0-G1 phase or at the S phase of human breast cancer (MDA-MB-468) and pancreatic cancer (Colo-357) cells, and loss of viability due to apoptosis. By contrast, cells treated with resveratrol, but lacking aberrant Stat3 activity, show reversible growth arrest and minimal loss of viability. Moreover, in malignant cells harboring constitutively-active Stat3, including human prostate cancer DU145 cells and v-Src-transformed mouse fibroblasts (NIH3T3/v-Src), resveratrol treatment represses Stat3-regulated cyclin D1 as well as Bcl-xL and Mcl-1 genes, suggesting that the antitumor cell activity of resveratrol is in part due to the blockade of Stat3-mediated dysregulation of growth and survival pathways. Our study is among the first to identify Src-Stat3 signaling as a target of resveratrol, further defining the mechanism of antitumor cell activity of resveratrol and raising its potential application in tumors with an activated Stat3 profile.

Controllable self-assembly of nanoparticles for specific delivery of multiple therapeutic molecules to cancer cells using RNA nanotechnology

By utilizing RNA nanotechnology, we engineered both therapeutic siRNA and a receptor-binding RNA aptamer into individual pRNAs of phi29's motor. The RNA building block harboring siRNA or other therapeutic molecules was fabricated subsequently into a trimer through the interaction of engineered right and left interlocking RNA loops. The incubation of the protein-free nanoscale particles containing the receptor-binding aptamer or other ligands resulted in the binding and co-entry of the trivalent therapeutic particles into cells, subsequently modulating the apoptosis of cancer cells and leukemia model lymphocytes in cell culture and animal trials. The use of such antigenicity-free 20-40 nm particles holds promise for the repeated long-term treatment of chronic diseases.

The Impact of Campath 1H Induction in Adult Liver Allotransplantation

BACKGROUND

We report our experience with Campath 1H in adult liver allotransplantation.

METHODS

Between December 2001 and February 2004, 77 patients underwent liver transplantation using Campath 1H induction and low-dose maintenance tacrolimus immunosuppression. The control group consisted of 50 patients with similar baseline characteristics and the same eligibility criteria, transplanted under our standard Tacrolimus/steroids regimen. Hepatitis C patients were excluded from the study.

RESULTS

Patient and graft survival were similar for both groups. The incidence of rejection was significantly lower in the Campath vs the control group (51% vs 65% at 12 months, P = .009). Tacrolimus trough levels and conversion from Tacrolimus or the addition of other immunosuppressive drugs due to nephrotoxicity were also significantly lower in the Campath 1H group.

CONCLUSION

Campath 1H induction with low-dose Tacrolimus maintenance immunosuppression is an effective regimen in reducing acute rejection in adult liver transplantation, while maintaining lower tacrolimus levels and less nephrotoxicity than our conventional immunosuppressive regimen.

Sclerosing mesenteritis in small bowel transplantation: possible manifestation of acute vascular rejection

BACKGROUND

Acute rejection of human small bowel allografts is characterized by clinical symptoms combined with characteristic morphologic alterations. The typical geographic distribution of acute rejection in the bowel is involvement of the intestinal parenchyma, which can be transmural, particularly when the rejection is more severe. However, little is known concerning the potential for donor-derived soft tissue adjacent to the bowel to become involved by the host alloimmune response.

METHODS

We describe a male patient who, several weeks after combined small bowel and liver transplantation, demonstrated sclerosing mesenteritis with vasculitis and acute rejection of the bowel.

RESULTS

The vascular lesions in the mesentery demonstrated increased IgG deposition and the patient developed an alloantibody to the donor.

CONCLUSIONS

The changes described herein may represent a novel presentation of acute vascular rejection.

Granulomatose septique chronique à révélation cutanée tardive

INTRODUCTION

Chronic septic granulomatosis is a disease characterized by an impaired bactericidal potential of the neutrophilic polynuclear. The cutaneous manifestations rarely reveal the disease, but are of considerable interest in the diagnosis, notably during the late onset forms. We report such a case.

CASE REPORT

A 15 year-old girl, born of consanguine parents, had a history of visceral leishmaniasis and hepatic hydatidosis. For the past 3 years she had developed dermatitis lesion on the face and skin folds, chronic folliculitis and suppurating axillary and inguinal lymphoadenitis. The absence of a reduction in tetrazolium nitro blue led to the diagnosis of chronic septic granulomatosis. Prophylactic treatment stabilized the cutaneous lesions.

DISCUSSION

Chronic septic granulomatosis regroups various severe and recurrent manifestations. Its transmission is usually X-linked recessive or, on rare occasions, autosomal recessive. The clinical manifestations leading to the diagnosis are often of very early onset. They are principally pneumonia due to apergillus fumigatus and lymphoadenitis. Cutaneous involvement, although less common, must not be neglected because it can lead to the diagnosis of late onset forms, as in our patient.

Morphological spectrum of polyoma virus disease in renal allografts: diagnostic accuracy of urine cytology

The morphological features of polyoma virus disease (PVDz) in 571 concurrent urine and biopsy samples from 413 patients are described. In 54 patients PV was found in both biopsy and urine samples. Histologically, PV presented as: (a) mild, viral cytopathic/cytolytic changes, with absent or minimal inflammation involving isolated tubules; (b) moderate and severe, cytopathic/cytolytic changes associated with patchy or diffuse tubulo-interstitial inflammation and atrophy; (c) advanced, graft sclerosis with rare or absent viral cytopathic changes, indistinguishable from chronic allograft nephropathy. Histological progression from mild to moderate or severe disease was seen in 28 patients. The mean post-transplantation time at diagnosis was similar in patients with mild or moderate-severe renal involvement (1.05 and 1.3 years, respectively). All patients presented with similarly increased values of serum creatinine (mean 1.35 mg/dL). There was strong correlation between the number of PV infected cells in urine and the concurrent biopsies (p = 0.0001). In 13 patients PV was found only in urine; of these, two developed PVDz later. The positive predictive value of a positive urine was 90%, the negative predictive value of a negative urine was 99% and the accuracy of the test was 97%. We conclude that urine cytology is useful to evaluate renal transplant patients with PV reactivation because sloughed tubular cells are found in urine and positive urine samples are a consistent manifestation of PV renal involvement.

Morphological spectrum of polyoma virus disease in renal allografts: diagnostic accuracy of urine cytology

The morphological features of polyoma virus disease (PVDz) in 571 concurrent urine and biopsy samples from 413 patients are described. In 54 patients PV was found in both biopsy and urine samples. Histologically, PV presented as: (a) mild, viral cytopathic/cytolytic changes, with absent or minimal inflammation involving isolated tubules; (b) moderate and severe, cytopathic/cytolytic changes associated with patchy or diffuse tubulo-interstitial inflammation and atrophy; (c) advanced, graft sclerosis with rare or absent viral cytopathic changes, indistinguishable from chronic allograft nephropathy. Histological progression from mild to moderate or severe disease was seen in 28 patients. The mean post-transplantation time at diagnosis was similar in patients with mild or moderate-severe renal involvement (1.05 and 1.3 years, respectively). All patients presented with similarly increased values of serum creatinine (mean 1.35 mg/dL). There was strong correlation between the number of PV infected cells in urine and the concurrent biopsies (p = 0.0001). In 13 patients PV was found only in urine; of these, two developed PVDz later. The positive predictive value of a positive urine was 90%, the negative predictive value of a negative urine was 99% and the accuracy of the test was 97%. We conclude that urine cytology is useful to evaluate renal transplant patients with PV reactivation because sloughed tubular cells are found in urine and positive urine samples are a consistent manifestation of PV renal involvement.

[Atopic dermatitis in Tunisia: epidemiological and clinical aspects]

INTRODUCTION

The prevalence of atopic dermatitis is usually high in western countries, varying from 18 p. 100 to 20 p. 100. Recent studies suggest an increasing of this frequency. The aim of our study is to determine the epidemiological and clinical characteristics of atopic dermatitis in Tunisia through the analysis of a retrospective cohort.

PATIENTS AND METHODS

We retrospectively studied all the medical reports of atopic dermatitis registrated in the department of dermatology during a 7 years period (1992-1998). We analysed epidemiological and clinical features of every medical report. We used diagnosis criteria of Hanifin and Rajka.

RESULTS

Four hundred fifty-one cases of atopic dermatitis have been diagnosed (54 adults and 397 infants). Relative frequency of new cases of atopic dermatitis compared to new diagnosis was 0.37 p. 100 in 1992 and 0.72 p. 100 in 1998. Mean age was 3.2 years. A personal history of atopy was observed for 15.2 p. 100 of patients and a family history of atopy for 35.9 p. 100. A few numbers of complications were observed. Bacterial infections interested 15.3 p. 100 of cases. Hospitalisation was needed for 4 patients (0.88 p. 100). Class III and IV topical corticosteroids were usually used (84.8 p. 100). Potent corticosteroids (class I) were required for only 3.2 p. 100 of cases.

CONCLUSIONS

We notice a low frequency of atopic dermatitis in this study and a predominance of mild forms of the disease. Other studies are needed to confirm these results and to determine the prevalence of atopic dermatitis in Tunisia.

Early progression stage of malignancy of uterine cervical dysplasia as revealed by immunohistochemical demonstration of increased DNA-instability

The degree of DNA-instability as revealed by the immunohistochemical staining with anti-single-stranded DNA antibody after acid hydrolysis (DNA-instability test) was used as a marker of malignancy. This was applied to mild dysplasia (42 cases), moderate dysplasia (43 cases), severe dysplasia (27 cases), squamous cell carcinoma in situ (CIS) (21 cases), invasive squamous cell carcinoma (SCC) (31 cases) and normal (7 cases) human uterine cervix. The expression of tumour suppressor gene p53 and oncogene bcl-2 was detected immunohistochemically. Proliferative activity was evaluated by PCNA immumohistochemistry and the quantitative analysis of the number, mean area, the largest area and maximum shape irregularities of AgNOR in a nucleus were performed for all these cases. The distribution of numeric chromosomal aberrations of chromosome 17 was also investigated in some of these cases. The results showed that 31 SCC (100%), 21 CIS (100%), 21 severe dysplasia (77.77%), 28 moderate dysplasia (65.11%), and 14 mild dysplasia (33.33%) were positively stained by the DNA-instability test diffusely or sporadically, indicating their malignancy. Reflecting the malignant character, these cases showed a remarkable increase in the PCNA-index with the loss of polarity of PCNA positive cell distribution and also an increase in number, mean and largest sizes and maximum shape irregularity of AgNOR dots. The mean chromosome index for chromosome 17, p53 and bcl-2 immunostaining positivity were also found to be significantly increased in moderate and severe dysplasia and in cancerous cases in comparison to normal and mild dysplasia cases. Moreover, the DNA-instability-test positive dysplasia cases showed statistically significant increased values of PCNA-index, AgNOR parameters, mean chromosome index, p53 and bcl-2 expression in comparison to those of DNA-instability-test negative dysplasia cases. In conclusion, some mild dysplasia (33.33%) and most of the moderate (65.11%) and severe dysplasia (77.77%) were regarded as malignant in nature, existing at an early stage of progression of malignancy.

Time-weighted average sampling of volatile and semi-volatile airborne organic compounds by the solid-phase microextraction device

The ultimate goal of the chemist is to perform sample preparation, and analysis, if possible at the place where a sample is located rather than moving the sample to laboratory, as is common practice in many cases at the present time. This approach eliminates errors and time associated with sample transport and storage and therefore it would result in more accurate, precise and faster analytical data. In addition to portability, two other important features of ideal field sample preparation technique are elimination of solvent use and integration with a sampling step. A method is developed which addresses these requirements for the determination of time-weighted average concentration of gas phase compounds using a solid-phase microextraction device. Quantification of target analytes in air using this method can be carried out without external calibration. The volatile and semi-volatile organic compounds in air diffuse into the fiber coating which is retracted a known distance into its needle housing during the sampling period. The coatings used are poly(dimethylsiloxane) and poly(dimethylsiloxane)-divinylbenzene. The sampling rate at which gas phase analytes load onto the fiber is determined for a wide range of hydrocarbons. There is a good agreement between the theoretical and experimental sampling rates. Sampling time ranges from 1 min to 24 h depending on the coating used and its retraction distance. Effect of the flow-rate on the uptake rate by the fiber is studied. The method is tested in the field and compared with National Institute of Occupational Health and Safety Method 1550. Good agreement between the results is obtained.

Monozygotic twins with MELAS-like syndrome lacking ragged red fibers and lactacidaemia

Typical cases of MELAS present a combination of clinical and neuroradiological features, lactacidaemia, and ragged red fibers (RRFs) in striated muscle. We have observed a MELAS-like syndrome in monozygotic twins. They developed seizures typically in conjunction with physical exertion, sleep deprivation or febrile episodes. Stroke-like episodes occurred usually during seizures. In twin 2 the course was fatal at age 20 years. Neuroradiological findings were typical of MELAS. Plasma lactate was normal in both. CSF lactate was normal in twin 1 and normal/elevated in twin 2. RRFs were not seen in muscle biopsies of the twins. Complex I activity was reduced in muscle in twin 1. Brain tissue removed at epilepsy surgery in twin 2 showed the presence of mitochondrial angiopathy. The commonest mitochondrial DNA mutation in MELAS, at base pair 3243, was absent. Lactacidaemia and mitochondrial myopathy with RRFs constitute part of the diagnostic criteria of MELAS. However, the absence of these features does not exclude mitochondrial disorder with the serious manifestations of MELAS (seizures and stroke-like episodes) as seen in these twins.

[Sialo-ultrasonographic approach of primary tuberculosis of the salivary glands. Apropos of 3 cases]

Primary tuberculotic involvement of the salivary glands makes up two per cent of all cases of salivary gland tumefaction that we have had to explore with ultrasonography and sialography. The patients are generally young adults of a low socioeconomic status. Sialography is nonspecific, whereas ultrasonography can suggest the diagnosis in the presence of heterogeneous, hypoechogenic intraglandular lesions associated to adenopathies. An IDR with tuberculin is essential for the diagnosis before treatment.