Rapid diagnosis of primary dengue fever by the immunochromatographic test and by electron microscopy - a case report

A 21-year-old woman presented with an acute febrile illness after a two-week holiday in Jamaica. Her symptoms started two days after return, with sudden onset of continuous high fever (> 39 degrees C), dizziness and nausea. Three days later she developed a generalized macular rash, which led to the tentative diagnosis "acute dengue fever." Laboratory confirmation was achieved by demonstrating anti-dengue IgM and IgG antibodies in paired sera; in addition, flavivirus particles were directly visualized by electron microscopy. (AU)

Ultrastructure of voluntary muscle in childhood malnutrition

This paper is part of a study on the electron microscopy of protein-energy malnutrition, using a rapid autopsy protocol. Samples of voluntary muscle, obtained from eight children dying of severe oedematous malnutrition, were fised in glutaraldehyde within 75 minutes of death. Atrophy of myofibres, increased prominence of satellite cells, and segmental necrobiosis were seen by light microscopy. Electron microscopy showed variable depletion of myofibrils. In the most severe case, there was focal absence of myofibrils, also disorganized Z lines, and absent M bands. Residual atrophic myofibrils measured less than 0.1 æm in width. Other specimens showed sarcomere disorganization, mitochondrial swelling, glycogen depletion, sarcoplasmic oedema, and focal contractions of sarcomeres. Though non-specific, rigor may phosphates. These conditions may exist in severe malnutrition, complicated by terminal infection and metabolic disturbances (AU)

Electron microscopy in Jamaica: applications and techniques

Although the electron microscope was developed about 60 years ago in Germany, its arrival and subsequent use in Jamaica are of considerably more recent date. In this paper, the principles of scanning and transmission electron microscopy (SEM & TEM) are briefly explained, and examples are given of the research done with the electron microscopes at the University of the West Indies (UWI), Mona Campus, Jamaica, especially over the last three years. Detailed descriptions of specimen preparation are provided for both SEM and TEM and particular emphasis is placed on the methodology used in our laboratory, as it sometimes differs from the routine followed in electron microscopy units of temperate countries. (AU)

Cutaneous myiasis due to dernatibia hominis: a report of six cases

We report six cases of Dermatobia hominis myiasis imported into the U.K. from Belize. With increasing international travel, myiasis may be encountered more frequently in countries in which the parasites are not indigenous. The life-cycle of D. hominis is described, and scanning electron micrographs show the detailed appearance of the larva (SUMMARY)

Pathology of the lungs in childhood malnutrition in Jamaica: light and electron microscopy

The autopsy records of 115 children with severe protein-energy malnutrition were reviewed. Sections of the lung histology showed evidence of bacterial pneumonia in 49 percent of cases. An additional 18 percentshowed bronchitis, bronchiolitis or interstitial pneumonitis. Aspiration of gastric contents was evident in 10 percent of cases; 6 percent showed pulmonary oedema and congestion. In the remaining cases, no lung pathology was identified (17 percent). In 8 cases, rapid autopsy examination permitted fixation of lung tissue for electron microscopy. These included 4 cases of bronchopneumonia, one of which was associated with viral pneumonia. Another interstitial pneumonitis, probably of viral aetiology, was also studied. Both these virus-associated cases showed loss of type I pneumocytes and hyperplasia of type II pneumocytes. Another patient with herpes simplex hepatitis showed necrotic emboli in pulmonary capillaries with virions, as well as colonies of interstitial bacteria. One patient with acute pulmonary oedema displayed severe endothelial cell swelling on electron microscopy. In one case, there was no evidence of respiratory changes, apart from desquamation of type I pnuemocytes. Useful information can be obtained on the fine structure of the lung, using samples taken soon after death. (AU)

Peroxisomes and the hepatic pathology of childhood malnutrition

Liver specimens obtained immediately after death from eight severly malnourished children were examined by electron microscopy, and compared with seven liver biopsy specimens from children who recovered from malnutrition. The liver cells from the fatal cases showed mitochondrial swelling, with coarse densities in the matrix, cholestasis, depletion of the endoplasmic reticulum and Golgi apparatus, diminished glycogen stores, prominent lipid deposits and focal cytoplasmic degradation. The nucleoli were enlarged. There was marked reducation in peroxisomes. In contrast, the biopsies from recovering children showed good cellular organisation, and a normal frequency of peroxisomes. Multiple factors, including sepsis, may lead to depletion of peroxisomes. Loss of peroximes may interrupt beta-oxidation of long-chain fatty acids and accentuate the accumulation of lipid. Moreover, a reduction in the concentration of catalase may remove one avenue for the detoxification of free radicals. As the concentration of other anti-oxidants, notably glutathione, is also reduced, free radical damage may occur, leading to lipid peroxidation of membranes, mitochondrial damage, pump failure and influx of water and electrolyted into the cell (AU)

Hepatic ultrastructure in children with protein-energy malnutrition

Samples of liver from eight children who died from malnutrition with its complications were studied by electron microscopy. Specimens were taken within one hour of death. These tissues had changes consistent with severe terminal illness, including mitochondrial swelling, with loss of matrix granules, disorganization of cristae, and evidence of calcium influx. Glycogen tended to be scanty. Lipid droplets were frequent. Endoplasmic membranes were depleted, and focal cytoplasmic degradation was frequent. Intracanalicular cholestasis was striking in four cases with loss of microvilli. Peroxisomes were depleted. This may be significant as peroxisomes are pivotal in the processing of very long-chain fatty acids in cholic acid metabolism and in elimination of free radicals. The observations were compared with previous reports in the literature, and with seven biopsies taken in 1970 from malnourished children who recovered. One, obtained on the fourth day, from a child with marasmus, showed atrophy of cellular organelles. The other samples were biopsied during the recovery phase, and displayed considerable restoration to normal morphology. Mitochondria had prominent matrix granules. Peroxisomes were frequently seen. There was no evidence of cholestasis (AU)

The exocrine pancreas in kwashiorkor and marasmus: light and electron microscopy

Histological sections of pancreas and liver from 65 cases of children dying from childhood malnutrition were reviewed. The extent of pancreatic atrophy and fibrosis was compared with fatty change in the liver. Pancreatic atrophy was common, and often associated with severe fatty change in the liver, but also occurred in marasmic children with scanty liver fat. Pancreatic fibrosis, when present, was only of mild degree. Among 16 patients with marasmus, fibrosis was only seen in one pancreas. Fibrosis was recorded in 8/25 cases of kwashiorkor, and in 7/24 cases diagnosed as marasmic-kwashiorkor. Electron microscopy of the pancreas was performed in seven cases, using tissue collected at immediate autopsy. Atrophy and variable amounts of degranulation of acinar cells were seen. There was often disorganization of the endoplasmic reticulum with intracisternal sequestration. Mitochondrial swelling was consistent with terminal anoxia. Centro-acinar cells were prominent. Some acini were dilated and contained fibrillar material. These findings support the pioneer paper by Blackburn and Vinijchaikul (1969) and underlie the importance of pancreatic atrophy in the pathology of protein-energy malnutrition. (AU)

Electron microscopy of herpes simplex hepatitis with hepatocyte pulmonary embolization in kwashiorkor

We report a case of herpes simplex hepatitis in a child with edematous malnutrition. Electron microscopy showed virus in parenchymal cells. With pulmonary embolization of necrotic, infected hepatic cell fragments. Systemic dissemination of herpes simplex may be related both to the profound immunoincompetence associated with kwashiorkor and to a reduction in the circulating and fixed polyanions that normally inhibit viral attachment to cells.(AU)

Warthin's tumour in Jamaica: incidence, electron microscopy and immunoenzyme studies

Warthin's tumour has traditionally had a strong male association, and has been said to be rare in Blacks. Current studies describe a newtrend; a rise in females, strongly linked to cigarette smoking. The tumour has eosinophilic epithelial cells packed with distinctive mitochondria, and a lymphoid stroma. Immunological investigations have demonstrated polyclonal B cells and macrophages. Views differ as to whether B or T cells predominate. Between 1958 and 1989, the Jamaica Cancer Registry recorded 491 benign and malignant salivary gland tumours. There were 18 cases of Warthin's tumour (3.7 percent), with a male:female ratio of 5:1. The low proportion of females is similar to the trend for female lung cancer in Kingston & St. Andrew. A case of Warthin's tumour was studied by light and electron microscopy and immunoenzyme methods. The epithelial cells contained numerous mitochondria with stacked cristae, as previously described. Similar morphology occurs in oncocytic tumours; riboflavin-deficient rats and mice; rats given non-lethal doses of hypoglycin; dogs treated with annatto extracts; and hibernating or starving frogs. The mitochondrial changes may be an adaptive response. The immunoenzyme studies utilized newly available monoclonalantibodies: UCHLI, L26, 4KB5, MT1 and LN2. The reaction patterns indicate a distribution of B and T cells in a manner expected in a lymph node. The interaction between mitochondrial changes adaptive metabolic pathways, the immune cells and tobacco raises some interesting questions (AU)

Effacement of glomerular foot processes in kwashiorkor

In a study of the pathogenesis of the oedema of kwashiorkor the ultrastructure of the kidneys from 6 children was examined shortly after they died from oedematous malnutrition. There was a generalised effacement of the glomerular epithelial cells onto the basement membrane. The filtration slits that remained were narrowed. The picture was similar to that seen in minimal-change nephrotic syndrome-but none of the children had albuminuria. The degree of effacement was statistically related to treatment with gentamicin. The findings suggest that there is a defect in the anionic charge of the glomerular basement membrane in oedematous malnutrition, that the membrane charge is more easily neutralised by cations such as gentamicin, and that, because proteinuria is not a feature of oedematous malnutrition, the proteinuria in other conditions associated with glomerular epithelial cell effacement (eg, minimal-change nephrotic syndrome) is due to something more complex than simple loss of charge.(AU)

Ultrastructure of the Islets of Langerhans in protein-energy malnutrition

Significant hormonal changes have been reported in childhood malnutrition, including high serum levels of growth hormone and cortisol, and low levels of circulating insulin. The ultrastructure of the endocrine pancreas in such patients has hitherto not been reported. A light microscopy survey of the pancreatic islets was carried out on 69 malnourished children dying from protein-energy malnutrition. In seven of these cases, a rapid autopsy protocol allowed tissues to be fixed for electron microscopy within 75 minutes of death. This paper presents the first ultrastuctural observations on the Islets of Langerhans in childhood protein-energy malnutrition. In all cases, there was a variable degree of degereration of all cell types with membrane damage, loss of ribosomes, vesiculation and mitochondrial swelling. In addition, the B-cells showed a high proportion of precursor granules compared to crystal forms, possibly accounting for low insulin serum levels reported by other workers. It is suggested that islet cell changes may be related to free radical damage secondary to depletion of glutathione and other antioxidants, as well as relative deficiencies of cysteine and zinc. In addition, the effects of agonal anoxia, and a short fixation delay after death must be considered. (AU)

Cell surface phenotype and human T lymphotropic virus type 1 antigen expression in 12 T cell lines derived from peripheral blood and cerebrospinal fluid of West Indian, Guyanese and African patients with tropical spastic paraparesis

Twelve long term cell lines were established from peripheral blood mononuclear cells (PBMC) or cerebrospinal fluid cells of patients with human T lymphotropic virus type I (HTLV-I) seropositive tropical spastic paraparesis (TSP) originating from the French West Indies, French Guyana or the Central African Republic. Most of these long term interlukin-2-dependent cell lines exhibited a pattern characteristic of CD4+ -activated T cells with high expression of CD2, CD3 and CD4 antigens, associated with a strong density of TAC and DR molecules. Nevertheless, in five cases CD8 expression was present at a significant level. HTLV-I antigens were expressed in a few cells after short-term culture and after 4 months the majority of the cells were HTLV-I positive, as demonstrated by indirect immunofluorescence (IF) using polyclonal or monoclonal anti-p19 and anti-p24 antibodies. Low and variable levels of reverse transcriptase activity were detected in supernatant fluids of these cell lines only after 4 months of culture, when at least 50 percent of the cells exhibited HTLV-I antigens by IF. However numerous type C HTLV-I-like viral particles were detected, mostly in the extracellular spaces, with rare budding particles. Similar findings were found in three T cell lines derived from West Indian and African patients with adult T-cell leukaemia/lymphoma (ATLL). Differences in high M-r polypeptides were detected by Western blot in cell lysates when comparing TSP-or ATLL-derived T cell lines. Thus a signal of 62K was easily detectable in all the TSP lines, but not in the ATLL lines. In all cell lines bands corresponding to p53, p24 and p19 viral core polypeptides were present, as was the env gene-coded protein p46. (AU)

Comparison of a human T-cell lymphotropic virus type I strain from cerebrospinal fluid of a Jamaican patient with tropical spastic paraparesis with a prototype human T-cell lymphotropic virus type I

The isolation and characterization of a human T-cell lymphotrophic virus type I (HTLV-I) from cerebrospinal fluid of a Jamaican patient with tropical spastic paraparesis is described. The virus isolate is a typical type C retrovirus as seen by electron microscopy and is related to prototype HTLV-I isolated from patients with adult T-cell leukemia but is not identical to this prototype HTLV-I as seen by restriction enzyme mapping.(AU)

Ultrastructural and neuropharmacological findings in the nerve/muscle system of a digenean (Cercaria caribbea LXXI Cable)

The surface morphology and organization of the neuromuscular system in Cercaria caribbea LXXI are investigated using scanning and transmission electron microscopy, respectively. Direct and indirect (sarconeural) nerve-muscle junctions are identified in the cercarial tail. Synaptic vesicles at the direct neuromuscular junction suggest cholinergic and aminoacidergic transmission. Those at the sarconeural junctions suggest catecholaminergic and/or serotonergic transmission. Acetylcholinesterase and non-specific cholinesterases were found in high concentrations in the proximal and distal tail. Flourescence histochemistry showed primary catecholamines and 5-HT in the body and tail. 5-HT in the tail may represent a slowly depleted store, perhaps associated with energy availability and utilization. (AU)

HTLV-I-like viral particles in spinal cord cells in Jamaican tropical spastic paraparesis

Viral-like particles morphologically identical to human T-lymphotropic virus type I or II, but distinct from human T-lymphotropic virus type III, have been seen by electron microscopy in spinal cord tissue from a Jamaican tropical spastic paraparesis patient who was known to be positive for human T-lymphotropic virus I antibody before death. This is the first electron microscopy report on a patient from an endemic tropical spastic paraparesis region. (AU)

Membranous glomerulonephropathy with crescents in systemic lupus erythematosus

Over a 2-year period percutaneous renal biopsies were carried out on 23 patients with systematic lupus nephritis. When classified by immunofluorescence, and light and electron microscopy, 4 patients had mesangial disease, 1 had focal and segmental proliferation, 5 had diffuse proliferation and 5 had membranous changes. 3 biopsies were unclassified with end-stage changes and 5 showed an unusual combination of pure membranous changes in association with significant crescent formation. The outcome of the latter group of patients was uniformly poor. We think that this group represents a distinct histological entity with a poor prognosis (AU)

Laboratory diagnosis of rotavirus infection in infantile gastroenteritis using the Elisa technique

The magnitude of gastroenteritis and its co-partner malnutrition has been amply identified in Jamaican children under five years but especially in the 6-24 month age group which are the most vulnerable. At present steps are being taken to significantly improve the existing conditions and the results have been very rewarding. Although the nutritional aspect was not emphasised in the analysis of this study it is a fact that malnutrition co-exists with gastroenteritis and the malnourished child is more prone to infection from the causative agents of gastroenteritis. Results of this show that rotaviruses are important aetiological agents of gastroenteritis in Jamaica especially in the "cooler" months of the year. The higher prevalence of rotavirus infection in Jamaican children (5 years and under) in December to March, the cooler months of the year is significant. This could suggest that temperature might play a role in the occurrence of the virus, in addition, there was a definite drop in temperature during those months. This pattern of higher prevalence in winter or cooler months is in accord with findings of other investigators worldwide (King et al, personal communication; Davidson et al; Bryden et a;; Kapikian et al; Middleton et al). From the findings in this study we can conclude that rotavirus appears to be significantly associated with Infantile Diarrhoea in Jamaican children, that there is a higher incidence in the cooler months of the year, and that there is correlation with previous studies by other investigators in different parts of the world in different aspects like clinical factors, age and sex, socio-economic status of the patients also climatological variables. Sensitivity, low cost, reagent stability, ease of procedure are some of the virtues of the ELISA. These factors are in favour of using this technique as a routine laboratory method of rotavirus detection. However, it must be remembered that optimum reproducibility is important, therefore these tests should be rigidly controlled by the inclusion of reference negative and positive antisera at all times and the specificity is further ensured by performing the Blocking Test. Although there are so many advantages in using the ELISA test routinely in a laboratory, there are also disadvantages. Among these are dependence on a foreign source for reagents and the possibility of the occurrence of false positives which calls for a blocking procedure, therefore prolonging the test results. However, the use of the ELISA technique in rotavirus detection would be beneficial to developing countries like Jamaica, if conjugate and control serum could be made available to them routinely by W.H.O. or similar health organization, or these reagents could be obtained from a reliable commercial source at a low affordable cost (Summary)