Febrile Illness and Intravenous Antimalarial Treatment at a District Hospital in Cameroon.

BACKGROUND: Malaria is one of the most common causes of mortality worldwide. The World Health Organization (WHO) has recently recommended that treatment should be guided by a laboratory diagnosis. The aim of this study is to explore patient and health care factors associated with intravenous antimalarial treatment of malaria test-negative patients at a district hospital in a malaria endemic area. STUDY DESIGN: A cross-sectional study of 91 patients admitted for intravenous antimalarial treatment was done at a district hospital in northern Cameroon in July and August 2010. Socio-cultural and clinical factors were studied in relation to quality blood smear results. RESULTS: Thirty-two per cent of all intravenous antimalarials were administered to patients with a negative malaria test. Test negative patients older than 40 years of age received significantly more often intravenous antimalarials than the youngest patients (OR = 7.9, 95% CI = 1.9-32.4, p = 0.004). Few differential diagnoses were identified in the study population, and patients older than 30 years of age had malaria less often than the youngest patients (OR = 0.3, 95% CI = 0.08-0.9 and OR = 0.09, 95% CI = 0.02-0.4). CONCLUSION: This study supports previous reports of over-diagnosis and treatment of malaria in endemic areas. The results suggest that differential diagnoses are important, especially in adults with febrile illnesses to ensure the correct diagnosis and treatment. Further studies are needed to explore the findings and to develop strategies to improve the management of malaria and its differential diagnoses.

The acceptability of volunteer, repeat blood donations in a hospital setting in the Adamaoua region of Cameroon.

BACKGROUND AND OBJECTIVES: The knowledge of factors that may influence blood donation in Cameroon is limited. The objectives of this study are to assess the characteristics of previous and potential blood donors by exploring the religious beliefs, and knowledge and understanding of blood donations among individuals present at a district hospital. MATERIALS AND METHODS: Forty-nine in-depth, semi-structured interviews were conducted among consenting, randomly selected 18 years or older community members present at a district hospital in the Adamaoua region during October and November 2011. RESULTS: Ninety-eight per cent (48/49) of the individuals present at this district hospital had heard of blood transfusions. Forty-seven per cent (23/49) had not previously been asked to donate blood; however, 94% (44/47) said that they would donate if given the opportunity. Thirty-three per cent (16/49) had previously donated blood to family members or for replacement, and 81% of these said they would repeat donations. The majority of both donors and non-donors were motivated to donate blood for altruistic reasons. CONCLUSION: The findings suggest that community members present at this district hospital in Cameroon may be recruited for repeat blood donations. Although the altruistic motivation to donate blood suggests that donors could be recruited from a district hospital population, targeted information about blood donations and accessible blood transfusion services need to be put in place. The study may add to the understanding of the preconditions for blood donations and the possibility to establish sustainable blood transfusion services in the Adamaoua region in Cameroon.

A study of blood transfusion services at a district hospital in Malawi.

BACKGROUND AND OBJECTIVES: Severe anaemia is an important cause of mortality in developing countries. However, few studies have explored the use of and possibilities for blood transfusion services. The aims of this study are to explore the use of blood transfusion services at a hospital in sub-Saharan Africa and to assess the quality of the transfusion services according to WHO guidelines. MATERIALS AND METHODS: Patient age, gender, haemoglobin (Hb) level, diagnosis, hospital department and replacement donations were recorded for all blood transfusions administered at a district hospital in Malawi in January 2010. The laboratory equipment and procedures were scored according to WHO guidelines. RESULTS: The mean Hb of transfused patients was 4·8 g/dl. Fifty-seven per cent (59/104) of the transfusions were given to children diagnosed with malaria, and 17% (18/104) were given to pregnant women. During the study period, blood was in stock and available for transfusion within 1 h of requisition. The equipment and procedures at this hospital met the main criteria for an adequate WHO stage of development. CONCLUSION: In contrast to the advanced transfusion medicine in developed nations, our findings highlight the persistent and urgent need for life-saving blood transfusions in especially young children and pregnant women in Africa. The results indicate that blood transfusion services adapted to local conditions may be a realistic solution for providing safe blood products in developing countries. Serious challenges, such as HIV transmission and sustainable organization of low-risk blood donations should be addressed to assure access to safe blood products.

Effects of serum-free storage on morphology, phenotype, and viability of ex vivo cultured human conjunctival epithelium.

The use of amniotic membrane (AM) represents one of the major developments in ocular surface reconstruction. However, in a study on patients with primary pterygium, transplantation of AM with ex vivo expanded human conjunctival epithelial cells (HCjE) promoted earlier epithelialization than AM alone. We previously showed that cultured human limbal epithelial cells maintain their morphology, phenotype, and viability for one week when stored at 23°C. The current study investigates the feasibility of storing HCjE in HEPES-MEM and Optisol-GS at 23°C for 4 and 7 days, respectively. The five experimental groups were analyzed by light microscopy, immunohistochemistry, transmission electron microscopy, and a viability assay. The ultrastructural integrity of cultured HCjE was well preserved following 4 days of storage, however, 7 days of storage resulted in some loss of cell-cell contacts and epithelial detachment from the amniotic membrane. The number of microvilli in cultured HCjE not subjected to storage was 2.03±0.38 microvilli/µm. In comparison, after 4 and 7 days of HEPES-MEM storage this number was 1.69±0.54 microvilli/µm; P=0.98 and 0.89±1.0 microvilli/µm; P=0.28, respectively. After Optisol-GS storage for 4 and 7 days, the mean number of microvilli was 1.07±1.0 microvilli/µm; P=0.47 and 0.07±0.07 microvilli/µm; P=0.03, respectively. The number of cell layers in cultured HCjE not subjected to storage was 4.4±0.3 cell layers, as opposed to 4.0±0.9 cell layers; P=0.89 after 4 days of HEPES-MEM storage and 2.8±0.6 cell layers; P=0.01 after 7 days of storage in HEPES-MEM. The number of cell layers after 4 and 7 days of storage in Optisol-GS was 3.7±0.2 cell layers; P=0.46 and 3.4±0.4 cell layers; P=0.18, respectively. The expression of markers for undifferentiated cells (ΔNp63α, ABCG2 and p63), proliferating cells (Ki67 and PCNA), goblet cells (Ck7 and MUC5AC), stratified squamous epithelial cells (Ck4), and apoptotic cells (caspase-3) in cultured HCjE appeared to be unchanged after 4 and 7 days of HEPES-MEM and Optisol-GS storage. The percentage of viable cells in cultured HCjE not subjected to storage (91.4%±3.2%) was sustained after 4 and 7 days of storage in HEPES-MEM (94.1%±4.5%; P=0.99 and 85.1%±13.7%; P=0.87, respectively) as well as after 4 and 7 days of storage in Optisol-GS (87.7%±15.2%; P=0.97 and 79.8%±15.7%; P=0.48, respectively). We conclude that cultured HCjE may be stored for at least 4 days in serum-free conditions at 23°C while maintaining the phenotype and viability. HEPES-MEM appears to be comparable to Optisol-GS for serum-free storage with preservation of the ultrastructure for at least 4 days.

Lymphocyte characterization of decidua basalis spiral arteries with acute atherosis in preeclamptic and normotensive pregnancies.

Uteroplacental acute atherosis (AA) is a common spiral arterial lesion in preeclampsia, characterized by intramural foam cells, fibrinoid necrosis, and a perivascular immune cell infiltrate. A clear definition of this infiltrate is lacking. Therefore, our aim was to characterize lymphocytes in pre-defined zones regarding spiral arteries with or without AA, from preeclamptic and normotensive pregnancies. Lymphocytes were characterized in decidua basalis samples (n = 91), previously evaluated for AA, around spiral arteries in three pre-defined zones; 1) intramural, 2) perivascular and 3) interstitial. Adjacent serial sections were immunostained to identify different T-cell populations (CD3+, CD8+, FOXP3+), and NK-cells (CD56+). CD3+CD8- T-cells were also identified. These were presumed to be largely CD4+ T-cells. AA was associated with significantly higher intramural CD3+ cell concentrations in Zone 1, in both normotensives and preeclamptics. In preeclamptics only, this difference extended into Zone 2. Similar results were observed for CD3+CD8- cells. AA was also associated with increased intramural CD8+ concentration; however, the number of cells was low. Regulatory T-cells (FOXP3+) were generally scarce or absent in all pre-defined zones. Although intramural NK-cells (CD56+) were scarce, the intramural concentration was significantly lower in spiral arteries with AA compared to without AA in preeclamptics. Our main finding was that CD3+CD8-FoxP3- T-cells were associated with AA. We therefore suggest that T-cells, of a non-regulatory CD4+ subtype, could be involved in the formation of spiral artery AA in the decidua basalis. Whether AA gives rise to, or is partly mediated by increased T-cell concentration around the lesions, remains to be determined.

Effects of explant size on epithelial outgrowth, thickness, stratification, ultrastructure and phenotype of cultured limbal epithelial cells.

PURPOSE: Transplantation of limbal stem cells is a promising therapy for limbal stem cell deficiency. Limbal cells can be harvested from either a healthy part of the patient's eye or the eye of a donor. Small explants are less likely to inflict injury to the donor site. We investigated the effects of limbal explant size on multiple characteristics known to be important for transplant function. METHODS: Human limbal epithelial cells were expanded from large versus small explants (3 versus 1 mm of the corneal circumference) for 3 weeks and characterized by light microscopy, immunohistochemistry, and transmission electron microscopy. Epithelial thickness, stratification, outgrowth, ultrastructure and phenotype were assessed. RESULTS: Epithelial thickness and stratification were similar between the groups. Outgrowth size correlated positively with explant size (r = 0.37; P = 0.01), whereas fold growth correlated negatively with explant size (r = -0.55; P < 0.0001). Percentage of cells expressing the limbal epithelial cell marker K19 was higher in cells derived from large explants (99.1±1.2%) compared to cells derived from small explants (93.2±13.6%, P = 0.024). The percentage of cells expressing ABCG2, integrin ß1, p63, and p63α that are markers suggestive of an immature phenotype; Keratin 3, Connexin 43, and E-Cadherin that are markers of differentiation; and Ki67 and PCNA that indicate cell proliferation were equal in both groups. Desmosome and hemidesmosome densities were equal between the groups. CONCLUSION: For donor- and culture conditions used in the present study, large explants are preferable to small in terms of outgrowth area. As regards limbal epithelial cell thickness, stratification, mechanical strength, and the attainment of a predominantly immature phenotype, both large and small explants are sufficient.

Effect of Transportation on Cultured Limbal Epithelial Sheets for Worldwide Treatment of Limbal Stem Cell Deficiency.

Limbal stem cell deficiency can be treated with transplantation of cultured human limbal epithelial cells (LEC). It can be advantageous to produce LEC in centralized labs and thereafter ship them to eye clinics. The present study used transport simulations of LEC to determine if vigorous shaking during transport altered the viability, morphology and phenotype during a 4 day-long storage of LEC with a previously described serum-free storage method. Inserts with LEC cultured on amniotic membranes were sutured to caps inside air-tight containers with generous amounts of 4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid (HEPES)-buffered minimal essential medium (MEM). The containers were distributed among the following testing conditions: 6 hours with full containers, 36 hours with full containers, 36 hours with container three quarters full of medium, and 36 hours with container full of medium containing a shear-protecting agent (Pluronic-F68). Compared to stored, but non-transported controls, no statistically significant changes in viability and immunohistochemical staining were observed. The epithelial sheets remained intact. However, an air-liquid interface in the containers reduced the number of desmosomes and hemi-desmosomes compared to the controls. In conclusion, cultured LEC sheets appear to endure vigorous shaking for at least 36 hours if the container is full.

Acute atherosis in decidual tissue: not associated with systemic oxidative stress in preeclampsia.

The aim of this study was to explore a possible association between the presence of decidual acute atherosis, maternal hyperlipidaemia and oxidative stress in the maternal circulation in preeclamptic and uneventful pregnancies. Decidual tissue was harvested by a vacuum suction technique following delivery of the baby and placenta in 102 caesarean deliveries. Maternal plasma lipid profile and concentration of 8-isoprostane, a marker of oxidative stress, was analysed. Acute atherosis was present in 42% of the preeclamptic patients with identified spiral arteries. CD68 positive foam cells were found in the spiral artery walls in 14% of the normal pregnancies. We have previously demonstrated an elevated plasma level of 8-isoprostane in the preeclampsia group, as compared to the uneventful pregnancy group (218 vs. 354 pg/mL, p=0.02). Presence of acute atherosis was, however, not associated with an elevated level of oxidative stress in the maternal circulation, measured as 8-isoprostane. In conclusion, the presence of decidual vascular changes in the form of acute atherosis is not necessarily paralleled by hyperlipidaemia or augmented oxidative stress in the maternal systemic circulation. This study adds to the notion of preeclampsia being a multifactorial disease with a variety of clinical forms.

Clinical prognostic factors in 1277 patients with neuroblastoma: results of The European Neuroblastoma Study Group 'Survey' 1982-1992.

In 1982 the European Neuroblastoma Study Group (ENSG) established a prospective registry for patients with newly diagnosed neuroblastoma ('The ENSG Survey'). Clinical information was collected primarily to: (a) establish an ENSG database; and (b) investigate prognostic factors in neuroblastoma. This paper summarises the results of the survey. By 1992, 1277 patients with a median age of 26 months (range: 0-289 months), gender ratio of 1.19 M:F had been registered from 30 centres. The median follow-up of survivors is 9.7 years (range: 1-14 years). Overall 5-year survival (S) is 45% (95% CI 42-48%), and event-free survival (EFS) is 43% (95% CI 40-45%). For both survival and EFS the key established prognostic factors, stage and age, are highly significant (P<0.001). In particular, patients under 1 year of age at diagnosis, whatever the disease stage, had a more favourable prognosis than older patients; stage 2 (EFS 93% (95% (CI 85-97) versus 76% (95% CI 67-86), P=0.02), stage 3 (EFS 91% (95% CI 82-96) versus 52% (95% CI 44-60), P<0.001) and stage 4 (EFS 59% (95% CI 48-69) versus 16% (95% CI 13-19), P<0.001). Multivariate analysis established that the anatomical location of the primary tumour (i.e. abdominal versus other sites) and primary tumour volume also conferred a statistically significant difference. In stage 4 disease the 20% of patients without demonstrable bone marrow involvement had a more favourable prognosis than those with infiltrated marrow (EFS 36% (95% CI 13-19) versus 16% (95% CI 29-45), P<0.001). Urine catecholamine metabolite levels (raised versus normal), histology (ganglioneuroblastoma versus neuroblastoma) and gender had no significant effect on outcome after stage and age were accounted for. 5-year survival following first relapse is only 5.6% (95% CI 2.8-8.4). This ENSG Survey provides secure data for future comparisons with new prognostic factors and treatment programmes.

Sibs with anencephaly, anophthalmia, clefts, omphalocele, and polydactyly: hydrolethalus or acrocallosal syndrome?

Major characteristics of the acrocallosal syndrome include severe mental retardation, agenesis or hypoplasia of the corpus callosum, and polydactyly of fingers and toes. In the past few years, anencephaly has also been noted, together with other midline defects. We report on a nonconsanguineous, Norwegian couple with a history of two pregnancies with a male and a female fetus, respectively, with anencephaly, median cleft lip and palate, omphalocele, and preaxial polydactyly, suggesting the diagnosis of the acrocallosal syndrome. Both fetuses also lacked eyes and nose, a finding not previously reported in the acrocallosal syndrome. Microphthalmia has been reported in the hydrolethalus syndrome, which may be caused by mutations in the same gene as the acrocallosal syndrome. The present report adds support to the hypothesis that the acrocallosal and hydrolethalus syndromes may be allelic conditions. The family history is consistent with autosomal recessive inheritance.

The use of post-embedding immunoelectron microscopy in the diagnosis of glomerular diseases. Comparison of immunoelectron microscopic and immunofluorescence studies.

Fifty renal biopsies were studied by immunoelectron microscopy after embedding in a partly hydrophilic polyacrylic resin (LR White). Immunofluorescence studies were carried out on frozen sections of parallel tissue samples. Polyacrylic embedding gave good preservation of the renal ultrastructure and precise localization of immunoglobulin and C3c antibodies within glomerular electron-dense deposits. Non-specific staining of plasma proteins within vascular lumina could easily be detected. There was good correlation between immunoelectron and immunofluorescence microscopy. Immunoelectron microscopy is a very sensitive method, which can detect small amounts of antigen. More cases were, however, positive by immunofluorescence than by immunoelectron microscopy. This discrepancy may be explained by difference in sample size, and by difference in resolution of morphological details (electron microscopy versus fluorescence microscopy).

Central review of bone marrow biopsy specimens from patients with neuroblastoma.

In order to achieve some uniformity in histological detection of bone marrow infiltration by neuroblastoma and to provide a measure of variation in histological opinions, sections from 712 evaluable trephine biopsy cores from children in a European Neuroblastoma Study Group (ENSG) study were reviewed centrally. Biopsy specimens were graded as tumour positive or negative. Discordance between local and central review opinions was found in 5% of specimens. Only five of 165 children at presentation and nine of 256 re-staging procedures in 126 children, affecting one child each, had their diagnosis upgraded to positive. In six re-staging procedures, affecting one child each, the diagnosis was downgraded. The low discordance rate is encouraging and substantially less important than previously documented difficulties in obtaining adequate specimens.

Adequacy of bone marrow trephine biopsy specimens in children.

AIMS: To evaluate success in obtaining adequate bone marrow trephine biopsy cores from children. METHODS: Sections of trephine biopsy cores submitted by 25 centres from children with neuroblastoma over a five year period were reviewed centrally. In cores containing no tumour adequacy was defined as 0.5 cm of well preserved bone marrow after processing. Occasional smaller cores containing obvious tumour were also considered adequate. RESULTS: Of 822 biopsy specimens, 139 (17%) were inadequate. In 13 centres submitting at least 20 cores failure rates ranged from 2.6 to 50%. There was no improvement over the five years of the study. There was no practically important correlation between the numbers of cores submitted and success in obtaining adequate specimens. Although a lower rate of inadequate biopsy specimens was found when haematologists rather than paediatricians (13 v 29%) were the predominant operators this should not be overinterpreted, not least because of the potentially confounding association between haematologist operators and larger numbers of biopsy specimens, and because the arbitrary subdivision of centres according to operator specialty was crude. The skill of individual operators could not be assessed. CONCLUSIONS: Many operators do not obtain adequate bone marrow biopsy specimens from children. Improvement is necessary because this is an invasive investigation, often performed under general anaesthesia. Reporting pathologists are well placed to influence practice by pointing out inadequacies in the specimen and suggesting retraining or even a change in operator. Improvement would almost certainly occur if this investigation was restricted to locally recognised successful operators, whatever their specialty. Most centres should review their practice and devise strategies to improve their ability to obtain adequate cores.

Deterioration in performance in obtaining bone marrow trephine biopsy cores from children. European Neuroblastoma Study Group.

AIM: To complete an audit of bone marrow trephine biopsy adequacy in children MATERIAL: 605 specimens from children with neuroblastoma submitted by 25 centres were reviewed centrally. This reassessment ran between January 1995 and August 1998. RESULTS: 25% of specimens (95% confidence interval (CI) 21% to 29%) were inadequate compared with 17% (95% CI 14% to 20%) in a previous study. Variation between individual centres' performance remains high (5-54% of specimens inadequate). Had five centres performed as well as previously, the inadequate biopsy rate would have been unchanged from that found in the previous study. There was no important improvement in any centre's performance. Earlier suggestions about change in practice have had no discernible impact on centres' ability to obtain adequate bone marrow trephine biopsies from children. CONCLUSIONS: The responsibility for improving the rate of adequate biopsies lies with individual centres. Reporting pathologists might help by making even more positive attempts to influence operators within their own centres.

Diagnosis of female genital schistosomiasis by indirect disease markers: determination of eosinophil cationic protein, neopterin and IgA in vaginal fluid and swab eluates.

Based on assumptions about the pathophysiology of egg-related lesions in the lower reproductive tract, putative indirect disease markers were investigated in vaginal fluids from 54 Malawi adolescent girls and women infected with S. haematobium. These women received a careful gynecological examination during which biopsies were taken from the cervix, and, if present, also from suspicious lesions in the vagina and the vulva. If the biopsies, either in wet crushed preparations or in histological sections, contained eggs the patients were considered to have female genital schistosomiasis (FGS; n = 33). The remainder (n = 21) were classified as having urinary schistosomiasis only. Eosinophil cationic protein (ECP), a cytotoxic granule protein of eosinophils, neopterin, a second messenger molecule generated during the activation of macrophages, and IgA as an indicator of local B-cell activation were quantitatively determined in vaginal fluid. To clarify the origin of ECP, this protein was also looked for in histological sections by an immunohistochemical method. In order to explore whether such disease markers can be detected after absorption to a tampon-like material, ECP and IgA were also assessed after elution from a non-porous, polypropylene fibre web impregnated with vaginal fluid. The concentration of ECP in vaginal fluid and the degree of immunohistochemical staining in histological sections were significantly higher in patients with FGS than in women with urinary schistosomiasis only. The amount of ECP detected in histological sections correlated to the number of eggs/mm2 of compressed genital tissue (rho = 0.36, P = 0.02), and the concentration of ECP in vaginal fluid correlated to the concentration of neopterin as well as to that of IgA (rho = 0.52, P = 0.004 and rho = 0.37, P = 0.02, respectively). Median neopterin concentration in vaginal fluid was also higher in the FGS group, but the difference was not statistically significant. ECP could also be detected in eluates from impregnated fibre webs, but the concentration was approximately one power of 10 less than in the original vaginal fluid. These results demonstrate that indicators of immunological mechanisms related to the egg-granuloma might be useful as indirect disease markers for women with FGS if assessed in vaginal washings or swab eluates.

Female genital schistosomiasis (FGS): relationship between gynecological and histopathological findings.

Schistosomiasis of the lower female reproductive tract manifests itself in a broad spectrum of clinical features. However, clinical and histopathological findings have never been studied in a synoptic manner. Based on the assumption that any type of pathology present in the female reproductive tract is the expression of a complex pathophysiological reaction towards eggs sequestered in the genital tissues, we decided to analyze colposcopic and histopathological findings in a comprehensive manner. Thirty-three women in Malawi with urinary and genital schistosomiasis were examined parasitologically and gynecologically. A thorough colposcopic examination with photodocumentation was performed and biopsies were taken from the cervix, the vagina and/or the vulva for histological sectioning and immunohistochemistry. The predominant colposcopic findings were sandy patches on the cervical surface similar to those seen in the bladder and polypous/papillomatous tumors with irregular surface on the vaginal wall and in the vulvar area. The histopathological sections of sandy-patch-like lesions demonstrated only a small cellular reaction around S. haematobium eggs in various stages of disintegration. In contrast, in the case of polyps the histology revealed a more pronounced immunological reaction characterized by a heavy cellular infiltrate. One case of invasive squamous cell carcinoma of the cervix was diagnosed. We conclude that colposcopy is a useful tool in the detection of FGS related pathology in the lower female reproductive tract and that the synoptic assessment of surface and of corresponding histological sections helped to understand the pathophysiology of S. haematobium associated disease in genital tissue.

Initial interactions of platelets and plasma proteins in flowing non-anticoagulated human blood with the artificial surfaces Dacron and PTFE.

The purpose of the present study was to investigate and to compare the interactions of platelets and proteins in flowing non-anticoagulated human blood with the biomaterials polyethylene-terephthalate (Dacron) and polytetrafluoroethylene (PTFE, Teflon). The respective biomaterials were positioned in a parallel-plate perfusion chamber, and exposed to flowing blood for 5 min at wall shear rates characteristic for veins (100/s), medium sized (650/s) and moderately stenosed arteries (2,600/s). Blood-material interactions were morphologically quantified as platelet-surface adhesion, thrombus volume and fibrin deposition. Platelet adhesion to Dacron was highest at the lowest shear rate (13%) and decreased with increasing shear (4% at 2600/s). In contrast, platelet adhesion to PTFE was shear rate independent (17-19%), and significantly higher than the adhesion to Dacron at 2600/s (P < 0.05). A hallmark of the platelets adherent to PTFE and Dacron was the large percentage of platelets not spread out on the surface. This indicates that both materials were poor platelet activators, even though immunostaining demonstrated the adsorption of the platelet adhesive proteins von Willebrand factor and fibronectin. Adsorption of fibrinogen was also prevailing on both materials. Virtually no thrombi formed on Dacron, while a few small platelet thrombi were observed on PTFE. Less than 1% of the Dacron and PTFE surfaces were covered by fibrin, irrespective of the shear rate. Thus, Dacron and PTFE interact differently with flowing non-anticoagulated human blood, and Dacron is apparently the least thrombogenic material.

Immunohistochemistry on needle biopsies of childhood malignancies.

Ultrasound-guided percutaneous needle biopsy proved to be a reliable and safe method to obtain material for histopathological and immunohistochemical diagnosis prior to treatment in childhood malignancies. A principal tumour identification could be obtained by a combined morphological and phenotypic examination of 38 small-sized tumour biopsy specimens using a fairly limited panel of immunological reagents, including antibodies to leucocyte common antigen (CD 45), certain B- and T-cell markers, various intermediate filaments (cytokeratin, desmin and vimentin), and neuroblastoma cells (UJ 167.11, A2B5, and UJ 13A; the latter recognizes NCAM). Five undifferentiated neuroblastomas were all positive with the neuroblastoma antibodies but negative for the other markers, including vimentin. The negative reactivity for desmin and vimentin was the major immunohistochemical distinction between neuroblastomas and rhabdomyosarcomas. In addition, limited reactivity with the neuroblastoma antibodies was seen in blastematous parts of Wilms' tumour, duct-like structures in a hepatoblastoma, and in tumour cells in a few undifferentiated myelo- and lympho-proliferative lesions. This study shows the importance of a combined evaluation of morphology and the pattern of immunoreactivity employing multiple markers.

Rapid supplementary fixation in frozen sections: microwave versus conventional fixation. A double-blind comparative study.

The preservation of morphological details in frozen sections subjected to microwave-assisted fixation was compared with that in frozen sections subjected to snap fixation with either formalin/ethanol or ethanol alone. Especially nuclear details were better preserved after short microwave fixation. Ethanol alone gave the poorest results, with loss of nuclear details in the majority of the cases. In this study there was no significant difference between the morphological results obtained with a cheap domestic oven and that with a specialized microwave processor. Microwave-assisted fixation in frozen sections is a simple, rapid method. It is recommended for use in routine laboratories.

Respiratory tract viruses in otosclerotic lesions. An immunohistochemical study.

A series of viral antigens, including adenovirus, influenza A and B, parainfluenza types 1 and 3, measles, mumps, respiratory syncytial (RSV) and Epstein Barr (EBV) viruses was studied in a prospective series of stapes specimens from 24 consecutive patients operated on for otosclerosis. The stapes specimens were processed for light microscopy and immunohistochemistry. With the exception of one case of positive specific reactivity for anti-RSV antibody in one multinuclear osteoclastic cell, no specific reactivity was seen in the specimens. This was the case both in active (n = 8) and inactive (n = 16) otosclerotic lesions. The possibility of unspecific staining reactions is discussed.