Primary ciliary dyskinesia due to CCNO mutations-A genotype-phenotype correlation contribution.

Primary ciliary dyskinesia (PCD) is genetically and clinically heterogeneous. CCNO mutations are associated with chronic destructive lung disease and were first described in 2014. Early reports suggest that CCNO is mutated more frequently than expected, however, these are considered rare. We report on three eleven-year-old children with PCD due to CCNO mutations. All children presented early-onset respiratory symptoms, no cardiac or situs anomalies and moderate to severe clinical courses. Patients 1 and 3 were admitted to a neonatal intensive care unit due to respiratory distress. Patients 1 and 2 had atelectasis and lobar collapse, for which lobectomy was performed for patient 1. Patient 3 also presented otitis media with effusion with conductive hearing loss, requiring tympanostomy tube insertion twice. Diagnosis of PCD for all three required repeated nasal brushings, delaying diagnostic confirmation. Microscopy analysis revealed severely decreased numbers of cilia, but normal ultrastructure and uncoordinated beat pattern in the residual cilia. Surprisingly, the prevalence of pathogenic CCNO variants in our centre is higher than expected (three out of sixteen patients). Pathogenic variants in PCD-causing genes lead to specific ultrastructural defects, and there is a suggestion for genotype-phenotype association. However, there are little longitudinal data evaluating the impact of specific defects on disease progression, but a recent study showed a worse lung disease and poorer nutritional status. Concluding, this report underlies the importance of patient-oriented diagnosis and management in highly experienced PCD centres.

An experimental model for fatal malaria due to TNF-alpha-dependent hepatic damage.

While BALB/c mice survive infection with blood stages of Plasmodium chabaudi chabaudi (AS), 70% of DBA/2 mice die by day 9-11 of infection, both strains controlling parasitaemia. We describe here that infection of DBA/2 mice results in extensive, multifocal hepatocyte death. Antibody neutralization of TNF-alpha prevents both liver damage and death.

Supratentorial giant cell ependymoma.

Ependymomas account for 3 to 9% of all neuroepithelial tumors and, although occurring most often within the ventricular system, they may arise from the extraventricular parenchyma as well. Several histologic patterns of these neoplasm are well known, but little attention has been devoted to a variant composed of giant elements. We describe the case of a 13-year-old girl experiencing a 3-month history of partial seizures in whom cranial magnetic resonance imaging showed an extraventricular, right parietotemporal neoplasm, adherent to the overlying dura mater. Histologic, immunohistochemical and ultrastructural findings were consistent with those of a high-grade ependymoma. The tumor was characterized by the presence of a major component of pleomorphic giant cells, as also seen in pleomorphic xantoastrocytoma, subependymal giant cell astrocytoma and glioblastoma multiforme. Similar elements have been described in two filum terminale and one supratentorial, intraventricular ependymoma, respectively. Histologic and evolutional data of those and of our own case suggest that isolated giant cells are not necessarily linked to a bad prognosis in ependymomas.

Expression of CD44 isoforms in normal salivary gland tissue: an immunohistochemical and ultrastructural study.

We studied the expression of CD44 isoforms immunoreactivity in normal human salivary gland tissue, aiming at its full characterisation in normal epithelial and myoepithelial cell types. Optical immunohistochemistry techniques using monoclonal antibodies anti-CD44v3, CD44v4/5 and, for CD44v6, together with immunoelectron microscopy, were performed in serous, seromucinous and mucinous glands. Normal human breast and a case of lactating breast adenoma were used for comparative purposes and as controls. CD44v3 was positive in acinar and myoepithelial cells and was absent in mucin-producing cells from the different gland types. CD44v4/5 was consistently negative in all types of salivary tissue. CD44v6 was constantly positive in serous acinar cells, focally positive in basal cells of ducts, and myoepithelial cells consistently expressed it. At the ultrastructural level, CD44v6 was localised to the interdigitating processes of acinar cells, whenever they were not covered by basal lamina and to the cell membrane facing myoepithelial cells. In myoepithelial cells, immunolabelling was found at the membranes facing the acinar cells and in caveolae present at this interface. No labelling was found at cell membranes of both acinar and myoepithelial cells in contact with basal lamina or at the luminal aspect of the former. The finding of CD44v3 and v6 in myoepithelium of normal salivary glands may argue in favour of the role of these molecules in the regulation of growth and renewal of normal tissues and, potentially, on the morphogenesis of salivary gland neoplasms.

Clear cell meningioma variant and clinical aggressiveness.

The few reports about clear cell meningiomas (CCM) point to an inordinate clinical aggressiveness despite their histological benignity. We studied 5 CCM aiming to assess their clinicopathological, cytometric, and ultrastructural features. Two patients were females and 3 males, with a mean age of 36 years. Two tumors were spinal, one of the cerebral convexity, one of the tentorium-clinoid region, and one of the base of the skull. The first 3 were totally removed and have not recurred for a mean follow-up time of 40 months. The tentorium-clinoid and the skull base tumors had radical subtotal and partial resections, and recurred after 16 and 1.5 months, respectively. All tumors but one, a non-recurrent one, presented no signs of histological anaplasia. The proliferative capacity, as assessed by MIB-1 staining index (SI), of recurrent tumors was slightly higher than that of those tumors that did not recur. All cases showed DNA diploid pattern. Amianthoid-type fibers were disclosed on ultrastructural study. CCM arose in patients younger than those with other variants of meningioma, the spinal canal and the posterior fossa were the common sites. Finally, intracranial tumors were linked to an aggressive behavior.

Alveolar adenoma of the lung: further characterization of this uncommon tumour.

Alveolar adenoma of the lung is a poorly characterized, uncommon pulmonary lesion with proliferation of alveolar epithelium and septal mesenchyme. We describe the electron microscopy, immunohistochemistry and DNA flow cytometry in a case of alveolar adenoma in a 55-year-old woman. Alveolar adenoma appears to be a distinct benign neoplasm of the alveolar structures. Our findings further suggest that it is not a precursor of bronchioloalveolar carcinoma or other type II pneumocyte lesions of presumed malignant potential.

A case of GM1 gangliosidosis type I.

A six-month-old female gypsy child, the daughter of second degree cousins, born after a full-term pregnancy and normal delivery, is described. There was generalized neonatal edema. Abnormalities included psychomotor retardation from birth and progressive appearance of facial dysmorphism, organ enlargement, axial hypotonia, hypertonia in limbs, myoclonic jerks, optic atrophy and bilateral cherry-red spots. The diagnosis of GM1 type 1 gangliosidosis was confirmed by biochemical, enzymatic and ultrastructural findings.

Seroprevalence of HTLV-I in Portugal and evidence of double retrovirus infection of a healthy donor.

The prevalence of antibodies to HTLV-I in 5,475 Portuguese from 6 regions spanning the country was studied. Overall seroprevalence was 0.55%, indicating that Portugal is not an endemic area for this virus. Seropositives were distributed throughout the country, and no geographic clustering was observed. The seroprevalence of individuals who had lived in former Portuguese colonies in Africa (0.7%) was significantly higher than that of individuals who had not been in Africa (0.36%). An increase in seroprevalence with age was noted, and more females than males were antibody-positive, though not significantly so. Serum from one donor (1711), originating from Guinea-Bissau, was shown by Western blot and radioimmune precipitation to react with various proteins of HTLV-I, HIV-1 and -2, and SIV. Based on the serologic profiles and isolation of bona fide HTLV-I from her lymphocytes (confirmed by immunologic analysis, molecular cloning of the provirus and restriction enzyme analysis and sequencing of the DNA), together with the reactivity of her sera with an HIV-2 isolate obtained from her husband, we conclude that this donor was doubly infected with HTLV-I and HIV-2, rather than being the host to an as yet unidentified retrovirus.

Confronting cisternae in human hepatocellular carcinoma.

The Authors report the presence of confronting cisternae (CC) in two cases of poorly differentiated human hepatocellular carcinoma. They are interpreted as a peculiar phenotypical alteration of the tumor cells, probably related to a disturbance of the morphogenesis of nuclear and endoplasmic membranes.

Ultrastructure of bacilli and the bacillary origin of the macrophagic inclusions in Whipple's disease.

An electron microscopic and cytochemical study of the Whipple bacillus in jejunal biopsies from three untreated patients was made using fixation procedures developed for the satisfactory preservation of bacterial ultrastructure. The envelopes of the normal-looking bacilli present free in the lamina propria consisted of the following layers. (i) A cytoplasmic membrane with a triple-layered profile and a mean thickness (peak-to-peak distance) of 6.08 nm. (ii) A thick (20 nm) cell wall containing peptidoglycan; the wall had a hitherto undescribed inner layer that contained polysaccharides, possibly teichoic acids. (iii) Surrounding the cell wall, a surface membrane with a symmetric profile and a mean peak-to-peak distance of 4.74 nm. The ultrastructural pattern of the Whipple bacillus wall corresponds to that of Gram-positive bacteria, but with an additional surface membrane. This membrane is different from the outer membrane of Gram-negative bacteria because it has a symmetric profile, is thinner and has no periodic acid-Schiff (PAS)-positive components. Normal-looking bacilli were seen very rarely inside jejunal macrophages, but degenerating bacteria were abundant in these phagocytes. Electron microscopy and ultrastructural cytochemistry of Whipple bacilli inside jejunal macrophages of the three untreated patients showed that the degenerative process is a sequence that leads to the loss of bacillary forms and to the accumulation of bacterial remnants resistant to degradation by the macrophage. These remnants correspond to the innermost, polysaccharide-containing portion of the bacillus wall. The progressive accumulation of these PAS-positive wall remnants is the origin of the intramacrophagic inclusions that are important in the histological diagnosis of Whipple's disease. The reported results indicate that in the three patients studied, the Whipple bacillus multiplies extracellularly, the bacteria that are phagocytosed by macrophages being degraded.

Tubuloreticular structures in hepatic endothelial cells in a case of malignant melanoma liver metastasis.

The presence of tubuloreticular structures within hepatic endothelial cells in a case of malignant melanoma liver metastasis is described. This finding may reflect a host cell response to the neoplastic proliferation in the liver tissue, possible a host-tumor immunological reaction.