Complementary DNA sequence of the HLA‐B*3924 allele1

We have isolated the complete coding region of HLA‐B*39 from a Spanish Caucasoid, using a new PCR primer for its 5′ untranslated region. The cDNA matched partial genomic sequences of B*3924, an allele whose distribution appears to be restricted to Mediterranean and Arabian Caucasoids. A single amino acid change exclusive to B*3924 (threonine‐98) distinguishes it from B*3903.     

Gastrointestinal stromal tumours (GISTs) negative for KIT (CD117 antigen) immunoreactivity

Gastrointestinal stromal tumours (GISTs) are currently defined as mesenchymal tumours of the gastrointestinal tract that express KIT receptor tyrosine kinase. However, a small subgroup of tumours that fulfil the clinical and morphological criteria for GISTs lack KIT expression. So far, the biological features of these tumours have rarely been addressed. The present study describes seven gastrointestinal stromal neoplasms that presented clinicopathological features typical of GISTs but showed absence of CD117 expression as detected by immunohistochemistry. The tumours originated from the stomach (n = 5), duodenum (n = 1), and colon (n = 1), showing histologically either predominantly epithelioid (n = 3), mixed spindled and epithelioid (n = 2), or anaplastic/spindle cell (n = 2) type features. CD34 and alpha-smooth muscle actin (alpha-SMA) positivity was present in four and three tumours, respectively. Chromosomal analysis was performed in two cases, both showing losses of chromosomes 14, 22, and 1p, which is the characteristic feature of GISTs. Dual-colour interphase fluorescence in situ hybridization (FISH) analysis, utilizing chromosome 1p-, 14-, and 22-specific probes, revealed a similar cytogenetic profile in the remaining five tumour specimens. Mutational analysis of exons 9, 11, 13, and 17 of KIT, and exons 12 and 18 of PDGFRA was performed in all cases by denaturing high-pressure liquid chromatography (DHPLC) pre-screening, followed by direct sequencing. None of the tumours showed KIT mutant isoforms. Three tumours harboured PDGFRA exon 18 activating mutations; two were Asp --> Val(842) missense substitutions and one was a DIM842-844 amino acid deletion. KIT and PKC theta (protein activated in interstitial cells of Cajal and GISTs) expression was determined by western immunoblotting of the total cell lysates from three tumour biopsies. None of these three tumours expressed KIT, while all specimens showed expression of PKC theta protein. These findings indicate that there is a subgroup of KIT-negative GISTs that exhibit the same morphological, cytogenetic, and molecular features as KIT-positive tumours. While intragenic PDGFRA activating mutations are present in some of these tumours, the oncogenic events underlying the pathogenesis of the others remain unknown.     

Lower serum vitamin E concentrations in major depression. Another marker of lowered antioxidant defenses in that illness

OBJECTIVE: Major depression is associated with defective antioxidant defenses. Vitamin E is the major fat soluble antioxidant in the body. The aim of the present study is to examine serum vitamin E concentrations in major depressed patients versus normal volunteers. METHOD: Serum vitamin E concentrations were measured in 26 healthy volunteers and 42 major depressed patients by means of HPLC. Since vitamin E is a fat soluble vitamin, and serum vitamin E concentrations are strongly related to these of low-density-lipoprotein cholesterol (LDL-C) and triglycerides, we have adjusted the results for possible differences in these lipids. The numbers of peripheral blood leukocytes were measured. RESULTS: Patients with major depression had significantly lower serum vitamin E concentrations than healthy controls. The area under the ROC (receiver operating characteristics) curve was 83%. There were significant and negative correlations between serum vitamin E and number of total leukocytes and neutrophils. CONCLUSIONS: Major depression is accompanied by significantly lower serum vitamin E concentrations, suggesting lower antioxidant defenses against lipid peroxidation. The results could, in part, explain previous findings, which suggest increased lipid peroxidation in major depression.     

Apoptosis and apoptosis-associated perturbations of peripheral blood lymphocytes during HIV infection: comparison between AIDS patients and asymptomatic long-term non-progressors

This study was designed to compare the degree of lymphocyte apoptosis and Fas-Fas ligand (FasL) expression in AIDS patients and long-term non-progressors (LTNPs) and correlate these parameters with apoptosis-associated perturbations in lymphocyte function. LTNPs had a lower frequency of apoptotic CD4+ and CD8+ T cells compared with subjects with AIDS. This correlated with a lower frequency of cells expressing Fas and FasL. The frequency of selected lymphocyte populations exhibiting a disrupted mitochondrial transmembrane potential (DeltaPsim) and increased superoxide generation was lower in LTNPs than in patients with AIDS; these abnormalities were associated with lower levels of caspase-1 activation in LTNPs. The results indicate a significantly reduced level of apoptosis and apoptosis-associated parameters in LTNPs than in patients developing AIDS. Based on these findings, a crucial role for mitochondria can be predicted in the process of lymphocyte apoptosis during the evolution of AIDS.     

Cotrimoxazole therapy ofToxoplasma gondii encephalitis in AIDS patients

Twenty-four consecutive HIV-positive patients affected byToxoplasma gondii encephalitis received trimethoprim-sulfamethoxazole (cotrimoxazole) as acute-phase treatment. Two dosage regimens of cotrimoxazole were used: 40 mg/kg/day (12 patients) or 120 mg/kg/day (12 patients) of total compound (trimethoprim plus sulfamethoxazole). Clinical and radiological responses to treatment were evaluated, and the product-limit method for survival data analysis was used. Eighteen of 24 patients showed both a clinical and radiological response (75 % response rate). There were no differences in response rates between patients receiving the two dosage regimens of cotrimoxazole. Adverse reaction consisted of leukopenia (two cases) and skin rash (three cases) which led to the discontinuation of the drug in one case. These results suggest that a randomized, controlled clinical trial should be carried out comparing cotrimoxazole versus sulfadiazine-pyrimethamine in AIDS patients withToxoplasma gondii encephalitis.Deceased.     

Molecular cloning and characterization of a novel gene of Candida albicans,CDR1, conferring multiple resistance to drugs and antifungals

By functional complementation of a PDR5 null mutant of Saccharomyces cervisiae, we have cloned and sequenced the multidrug-resistance gene CDR1 of Candida albicans. Transformation by CDR1 of a PDR5-disrupted host hypersensitive to cycloheximide and chloramphenicol resulted in resistance to cycloheximide, chloramphenicol and other drugs, such as the antifungal miconazole, with collateral hypersensitivity to oligomycin, nystatin and 2,4 dinitrophenol. Our results also demonstrate the presence of several PDR5 complementing genes in C. albicans, displaying multidrug-resistance patterns different from PDR5 and CDR1. The nucleotide sequence of CDR1 revealed that, like PDR5, it encodes a putative membrane pump belonging to the ABC (ATP-binding cassette) superfamily. CDR1 encodes a 1501-residue protein of 169.9 kDa whose predicted structural organization is characterized by two homologous halves, each comprising a hydrophobic region with a set of six transmembrane stretches, preceded by a hydrophilic nucleotide binding fold.     

Correlation between the course of the medial plantar artery and the morphology of the abductor hallucis muscle

The abductor hallucis muscle flap is commonly used as a proximally-based flap in the management of ankle, heel, and midfoot lesions, where it is ideally suited for closing defects. This study investigates the anatomical details of this muscle in 13 fresh male cadavers. The medial plantar artery (MPA) was studied by dissection and macroscopic analyses to document the relationship of its superficial and deep branches with respect to the abductor hallucis muscle (AHM). Three main patterns could be described. In Pattern A (54%) the MPA divides into two branches. The deep branch reaches the deep surface of the AHM, supplying its proximal part, and the superficial branch courses between the AHM and the flexor digitorum brevis, to end as the first plantar metatarsal artery. The latter supplies two to three small branches to the distal part of the AHM. The fibers of the AHM end symmetrically on the two sides of the tendon and the muscle presents an arciform shape. The MPA, in Pattern B (38%), lacks a deep branch and continues along the lateral border of the AHM as a superficial branch that supplies proximal and distal collaterals to the muscle. The muscle fibers of the AHM end mainly on the medial side of the tendon. The muscle belly presents an arciform shape and is located on the medial margin of the foot superomedially with respect to Pattern A. In Pattern C (8%) the MPA continues as a large deep branch on the deep surface of the AHM and ends as the medial collateral artery of the big toe. A smaller superficial branch of the MPA provides a few collaterals to the AHM from its proximal part and to the flexor digitorum brevis in its distal part. The AHM fibers end mainly on the lateral side of the tendon and morphologically the muscle presents a straight line on the sole of the foot compared to Pattern A. Although Patterns B and C, from a surgical point of view, necessitate interruption of the main trunk of the MPA, Pattern A may permit the vascularization of the muscles of the medial side of the sole of the foot by the superficial trunk of the MPA. Because preoperative radiological study of the plantar vessels correlate with the morphological characteristics of the AHM observed during surgery, such imaging may be useful in determining the appropriate flap design based on the patient's unique pattern of MPA branching.     

Hurthle cell adenoma of the mediastinum: intraoperative cytology and differential diagnosis with correlative gross, histology, and ancillary studies

A 66-year-old man was found to have a 7.5 cm mediastinal mass detected on routine chest X-rays as part of his preoperative work up for an inguinal hernia repair. An orthotopic (normally located) nongoitrous thyroid gland without evidence of connection to the mediastinal mass was also identified. The clinical differential diagnoses included lymphoma, thymoma, and germ cell tumor. Fine-needle aspiration (FNA) biopsy smears and touch imprints of the mediastinal mass showed a loosely cohesive, highly cellular population of relatively uniform cells with abundant granular cytoplasm, low nuclear to cytoplasmic (N/C) ratios, and prominent nucleoli consistent with a Hurthle cell (HC) neoplasm. Subsequently, the diagnosis of HC adenoma was confirmed on the surgically excised mediastinal mass. To the best of our knowledge, the surgical pathology and cytologic features of an HC adenoma of the mediastinum have not been reported in the literature. The gross, histologic, immunohistochemical, and electron microscopic (EM) findings, in addition to the cytologic features, are presented along with a differential diagnosis of this mediastinal neoplasm.