Birgitta Carlén

The nexin-dynein regulatory complex subunit DRC1 is essential for motile cilia function in algae and humans

Primary ciliary dyskinesia (PCD) is characterized by dysfunction of respiratory cilia and sperm flagella and random determination of visceral asymmetry. Here, we identify the DRC1 subunit of the nexin-dynein regulatory complex (N-DRC), an axonemal structure critical for the regulation of dynein motors, and show that mutations in the gene encoding DRC1, CCDC164, are involved in PCD pathogenesis. Loss-of-function mutations disrupting DRC1 result in severe defects in assembly of the N-DRC structure and defective ciliary movement in Chlamydomonas reinhardtii and humans. Our results highlight a role for N-DRC integrity in regulating ciliary beating and provide the first direct evidence that mutations in DRC genes cause human disease.

Core-needle biopsy performed by the cytopathologist : A technique to complement fine-needle aspiration of soft tissue and bone lesions

Fine‐needle aspiration cytology (FNAC) is gaining increased popularity in the diagnosis of musculoskeletal lesions; and, in many patients, a definitive diagnosis can be rendered from aspiration smears alone. The main limitation of FNAC of soft tissue and bone neoplasms is in the evaluation of tissue architecture. In addition cytologic specimens are not always adequate for ancillary studies.

Pigmented villonodular synovitis: Monoclonality and metastasis—a case for neoplastic origin?

We report a 48-year follow-up of a case of recurrent pigmented villonodular synovitis of the knee. Subcutaneous metastasis to the contralateral thigh was an unusual finding. Histology demonstrated fibroblastic and histiocytic proliferation, as well as increased mitotic activity in recurrent lesions. Cytogenetic analyses demonstrated monoclonality and chromosomal abnormalities. Our findings support a neoplastic origin of this lesion.

Infection of BALB/c A mice by spiral and coccoid forms of Helicobacter pylori

Helicobacter pylori exists in two different morphological forms, spiral and coccoid. This study demonstrated that both forms can infect BALB/c A mice. The animals were inoculated orally three times at 2-day intervals with 10(8) cfu of both spiral and coccoid forms of strain CCUG 17874 (NCTC 11637), strain 25 and strain 553/93. Infection was followed over a 30-week period by histological scoring of the grade of inflammation in gastric biopsies. At each time point sera were collected for analysis in ELISA and immunoblot analysis. Both spiral and coccoid forms of all H. pylori strains gave significantly higher inflammation scores than a control group of animals 1 week after inoculation. The histological evidence persisted throughout the entire 30 weeks. The inflammation was most severe in the pylorus and duodenum. Infection with strain 553/93 displayed the most severe gastritis. The spiral form of strain CCUG 17874 gave an immune response after only 4 weeks, whereas its coccoid form as well as strains 25 and 553/93 (spiral and coccoid forms) gave a significant increase in antibody response in ELISA and immunoblot after 16 weeks. It is concluded that both spiral and coccoid forms of H. pylori can cause acute gastritis in BALB/c A mice.

Fine needle aspiration (FNA) in the diagnosis of soft tissue tumours; a review of 22 years experience

FNA plays an important role in preoperative diagnosis of soft tissue tumours. A close clinical/morphologic cooperation is essential. FNA should be performed on the most accessible part of the tumour, avoiding penetration of the deep portions of the tumour. Needles 0.7 mm (22 G) are recommended. For deep lesions, needles with a stylet should be used. After the FNA, tattooing of the aspiration channel is recommended, and the channel is surgically removed together with the tumour, if a sarcoma. Material from the FNA can be used for additional examinations, i.e. electron microscopy, immunohistochemistry, DNA ploidy analysis and chromosomal analysis. Those techniques are of great importance in the differential diagnosis, particularly in the paediatric small/round cell tumours. the majority of sarcomas can be defined as low grade or high grade malignant in FNA. For malignancy grading the following parameters are used: cellularity, pleomorphism, chromatin pattern, nucleolar structure, mitotic figures and necroses. Cytodiagnostic details of the most common soft tissue tumours and their differential diagnoses are presented.

Effects on the Ciliated Epithelium of Protein D—Producing and —Nonproducing Nontypeable Haemophilus influenzae in Nasopharyngeal Tissue Cultures

A pair of isogenic, nontypeable Haemophilus influenzae strains, one expressing protein D and the other protein D-negative, was compared in their ability to cause damage in a human nasopharyngeal tissue culture model. Damage was assessed by measuring the ciliary beat frequency (CBF) of tissue specimens at 12 h intervals. Cultures inoculated with H. influenzae manifested a decrease in CBF beginning after 12 h, with a maximum decrease after 36 h. The impairment of ciliary function by the protein D-expressing strain was significantly greater than that caused by the protein D-negative mutant (P<.01). Tissue specimens examined by scanning and transmission electron microscopy after 24 h appeared normal. After 48 h of incubation, the protein D-expressing strain caused a significant loss of cilia. These findings suggest that protein D is involved in the pathogenesis of upper respiratory tract infections due to nontypeable H. influenzae, probably by enhancing functional and morphological damage to cilia.

Chromosomal Abnormality T(9;22)(Q22;Q12) In an Extraskeletal Myxoid Chondrosarcoma Characterized By Fine Needle Aspiration Cytology, Electron Microscopy, Immunohistochemistry and Dna Flow Cytometry

A multidisciplinary approach was taken to characterize a soft tissue tumour. In smears prepared from aspirated material, uniform tumour cells, embedded in a myxoid matrix and partly arranged in a lace‐like pattern, were found. Histopathology showed a lace‐like pattern of cells in a matrix of hyaluronidase‐stable mucins. Cytoplasmic positivity for S‐100 protein was found in some tumour cells. Electron microscopic analysis revealed intracisternal aggregates of microtubules. All these features are consistent with the diagnosis of extraskeletal myxoid chondrosarcoma (EMC). DNA flow cytometry showed a diploid DNA content. Cytogenetic examination revealed the tumour karyotype 45, XY, t(2;11)(q31;p15), t(9;22)(q22.3;q12), dic(13;22)(p11;p13). Because similar 9;22‐translocations have been described in two other cases of EMC, we conclude that t(9;22)(q22–31;q11–12) is a specific rearrangement in this tumour type. Cytogenetic analysis may thus be of diagnostic value in the examination of tumours with this and similar histologies.

Primary Ciliary Dyskinesia: A Review

The entity sinusitis, bronchiectasis, and situs inversus is since long named Kartagener syndrome. Nowadays the designation used is primary ciliary dyskinesia (PCD), which implies cilia with decreased or total absence of motility, which may result in sinusitis, chronic bronchitis, bronchiectasis, and male infertility. A large number of deficiencies detectable on the ultrastructural level give rise to PCD. There may also be aberrations not detected up to the present. The normal left–right asymmetry of the body is thought to be due to the beating of the cilia in the embryonic (Hensens) node. Total immotility of the cilia should therefore result in random asymmetry of the body that is situs inversus in 50% of the cases. It has also been claimed that 50% of cases with PCD have situs inversus. However, several deficiencies apparently do not cause total immotility, and all ultrastructural variants are not associated with situs inversus in 50% of the cases. Several of the deficiencies are difficult to detect. Optimal fixation and handling are therefore obligatory. The genetic changes behind the variants are now being studied in several laboratories. Patients with PCD have very low levels of nasal nitric oxide, which is of increasing diagnostic importance. Other established diagnostic methods are the saccharine test and determination of ciliary beat frequency.

Fine needle aspiration (FNA) of synovial sarcoma—a comparative histological–cytological study of 15 cases, including immunohistochemical, electron microscopic and cytogenetic examination and DNA‐ploidy analysis

A retrospective study of 25 FNAs (11 aspirates from primary tumours and 14 from recurrencies and metastases) from 15 synovial sarcomas was performed. The cytological findings were correlated with the histopathology and the value of immunohistochemical and electron microscopic examination as well as DNA‐ploidy and cytogenetic analysis for diagnosis were assessed. A reproducible cellular pattern with a reliable diagnosis of spindle cell sarcoma was possible provided that the aspirates were cell rich. However, a true biphasic pattern indicative of synovial sarcoma was only seen in one of the 25 specimens. Electron microscopic examination of the aspirates was a valuable adjunctive diagnostic method, whereas immunocytochemistry and DNA‐ploidy analysis were not. Immunohistochemical, electron microscopic and cytogenetic analysis were all valuable ancillary methods when performed on surgical specimens. Malignant haemangiopericytoma and fibrosarcoma were the most important differential diagnoses in the FNA specimens.

Distinct cytologic features of spindle cell lipoma: A cytologic-histologic study with clinical, radiologic, electron microscopic, and cytogenetic correlations

Spindle cell lipoma (SCL) is a relatively uncommon, benign tumor that usually presents in the subcutaneous fat of adult men. Although some studies have addressed the histologic findings of SCL, only a few descriptions of aspiration cytology findings have been published. The cytologic features are poorly defined, and aspirates from SCL may cause diagnostic problems, because SCL shares some features with other fatty/spindle cell or myxoid lesions, benign as well as malignant.