The human materno-foetal relationship in malaria. II. Histological,ultrastructural and immunopathological studies of the placenta

Histological and ultrastructural studies of four placentae heavily infected with Plasmodium falciparum revealed large intervillous accumulations of erythrocytes containing parasites together with monocytes which had ingested pigment. These appearances were associated with focal syncytial necrosis, loss of syncytial microvilli and proliferation of cytotrophoblastic cells. In addition, marked irregular thickening of trophoblastic basement membranes and protrusion of tongue-like projections of syncytiotrophoblast into the basement membrane were observed. In six other placentae which contained scanty amounts of pigment but no parasites, representing past or inactive infection, no large collections of monocytes or abnormalities of trophoblast were apparent but basement membrane thickening was evident. Immunohistological studies revealed no significant differences between placentae positive for parasites and those containing pigment only, although the amount of certain immunoproteins and clotting factors was clearly increased above normal. These findings establish that P. falciparum infection in the placenta may result in substantial damage although lesions within the villus are rare. Furthermore, previous infection, although adequately controlled, may leave a heritage of pigment deposition, basement membrane thickening and immunopathological lesions. These results may thus account for both the high frequency of intra-uterine growth retardation and the rarity of congenital malaria in the presence of P. falciparum malaria.     

Species differences in the hepatic response to mirex: ultrastructural and histochemical studies.

Mirex was fed at levels of 1, 5, 15, and 30 ppm to mice, 5 and 30 ppm to rats, while monkeys received the chemical by stomach tube at levels of 0.25 and 1 mg/kg (equal to 5 and 20 ppm). Mice were killed and their livers obtained at 2, 4, 6, 9, 10, 15 and 18 months, whereas rats were killed and surgical biopsies were taken at 16, 19, 26, and 36 months. Cytochemical techniques were employed to detect activities of lysosomal beta-glycerol phosphatase (ACpase) and glucose 6-phosphatase (G-6-pase). ACpase and G-6-pase remained unchanged and comparable to controls in livers of mice receiving 1 ppm. G-6-pase decreased in centrilobular areas while ACpase increased with time in the higher groups. At 12 months, liver cells that lost their G-6-pase activity surrounded by Kupffer cells that contained strong ACpase. In contrast, rat livers had no increase in ACpase and little loss in G-6-pase. Surprisingly, and in spite of the high levels of mirex ingested, monkey livers showed no loss of G-6-pase or activation of ACpase. Ultrastructurally, the underlying feature in all livers was proliferation of smooth endoplasmic reticulum (SER) displaying species variation. Thus, in mice, intense proliferation of SER that was both time- and dose-dependent was localized in specific regions of the cytosol. Hepatic cells, damaged and necrotic in mice fed 5, 15, and 30 ppm, were phagocytosed by activated Kupffer cells. SER proliferation in rat and monkey liver cells was less conspicuous than in mice. Except for this change, rat and monkey liver cells were normal. There studies emphasize species and enzyme variations in response to mirex. An interesting aspect observed was the lack of lysosomal catabolism during liver enlargement.     

Tympanic epithelium: an ultrastructural, experimental and clinical study.

Ultrastructural studies of the guinea pig tympanic membrane failed to reveal specific morphological features that could be associated with migration. A staining method was used to study epithelial migration on 68 normal guinea pig tympanic membranes. A very predictable migratory pattern emerged which was neither influenced by perforation or ventilating tube insertion. Clinical studies in children on 61 normal tympanic membranes revealed a rapid migration which was unchanged by middle ear effusion. A centrifugal pattern of migration was observed in relation to the 23 chronic perforations studied. The kinetics of epithelium in relation to 41 ventilating tubes and in 23 retraction pockets is described.     

Heterozygous expression of Lesch-Nyhan syndrome clinical and ultrastructural studies

The study comprised two cases (male & female sibs) from one family, with Lesch-Nyhan Syndrome. They were subjected to clinical evaluation, pedigree construction, uric acid estimation in blood, urates in urine, metabolic screening of blood and urine for amino acids, examination of oral cavity, histological studies of the gingiva by light and electron microscopy as well as buccal smear for Barr & Y bodies (for the female). The proband, a six years old female presented with self-mutilation, mental retardation, hyperactivity and aggression. She had bitten her index finger causing amputation of its distal phalanx. On family study her younger brother (9 months) was found to have increased uric acid and less severe neurologic involvement. The serum uric acid level of the affected female was higher. Her Barr body showed normal pattern. Oral cavity examination showed no abnormalities. Histological examination of the gingiva showed macrophages around the blood vessels. Ultrastructural studies showed more or less normal epithelium. There was collection of macrophages around the blood vessels in the sub-epithelial layer, the cytoplasm of these macrophages contained stippled cytoplasmic inclusions. The surrounding connective tissue showed thin collagen fibers with sharp delineation between the epithelial and connective tissue layers indicating poor quality of collagen. There was no histological difference between the hemizygous male and the heterozygous female. The present study indicates heterozygous expression of Lesch-Nyhan Syndrome at both the clinical and the ultrastructural levels in favour of extreme lyonization or X-chromosome deletion in the affected female. Our findings also indicate that ultrastructural studies could be sensitive indicators of abnormal uric acid metabolism. Further studies are needed to compare the phenotypic expression of hemizygotes and heterozygotes with Lesch-Nyhan Syndrome at both the clinical and ultrastructural levels.     

Comparative response of male rats to parathion and lindane: histopathological and biochemical studies.

Exposure of male rats to parathion (2.6 mg/kg), lindane (17.6 mg/kg), or their combination through oral intubation daily for a period of 90 days produced histological and biochemical alterations in the liver and testis. The focal necrosis of the liver, although observed in all the treatments, was very prominent in the animals exposed to lindane alone. The kidney and epididymis, however, did not show any significant histological lesions. The activity of acetylcholine esterase in blood and brain decreased markedly, whereas that of succinic dehydrogenase, adenosine triphosphatase, and the alkaline and acid phosphate in liver and testis showed significant alterations for all three treatments.     

An epidemiological study of the relationship between occupations and acute herniated lumbar intervertebral discs.

A case-control study of the epidemiology of acute herniated lumbar intervertebral discs in the New Haven, Connecticut, area indicates that sedentary occupations increase the risk for herniated lumbar discs, particularly among those aged 35 years and older who have had sedentary jobs for several years. People in occupations requiring prolonged driving of motor vehicles, such as truck drivers, appear to be at particularly high risk. The results of this study provide no evidence that people whose jobs involve heavy manual labour are at greater risk for acute herniated lumbar disc than others of their age and sex.     

Cephazolin: clinical studies in obstetrics.

A clinical evaluation of a new cephalosporin, cephazolin, in obstetric patients is presented. Sixteen cardiac patients received the drug prophylactically as antibiotic cover during labour. Eighteen patients with miscellaneous antenatal and puerperal infections received the drug as primary treatment. The data obtained indicate adequate serum and tissue levels with the dose used, and corresponding clinical response. The impression is of a safe and efficaceous drug in the described obstetric situations requiring antibiotic therapy. It may be given prophylactically and with confidence to the cardiac patient in labour.     

Clinical,histopathological and genetic studies in a family with fatal familial insomnia

We compared clinical data from two related Chinese patients with fatal familial insomnia (FFI) and collected information about their pedigree. The clinical features in the two cases were similar and included initial progressive insomnia and sympathetic activation, which persisted throughout the clinical course. A total of 135 members of this family, across seven generations, were retrospectively investigated. Eleven family members, including the two FFI cases, were found to have died with similar neurological problems. Analysis of PRNP in 32 family members revealed eleven carrying the D178N allele, including the two FFI patients. Spongiform degeneration in brains was not found, but gliosis was obvious in the thalamus of the two cases at postmortem. Proteinase K-resistant prion protein (PrP) was not found in proband's brain by immunohistochemistry, but observed in some areas of brain for both cases by PrP-specific Western blot. Investigation of the pedigree has led to the identification of an additional 9 family members who had similar clinical symptoms and 9 currently healthy individuals with the D178N mutation.     

Testicular apoptosis after dietary zinc deficiency: ultrastructural and TUNEL studies

The present study was conducted in Wistar rats to determine whether prepubertal dietary zinc deficiency causes apoptotic changes in testes. Prepubertal male Wistar rats (40-50 gm) were divided into 3 groups: zinc control (ZC), pairfed (PF), and zinc deficient (ZD). Control and pairfed groups were given a 100 ppm zinc diet while the deficient groups received 1 ppm zinc diet for 2 and 4 weeks (w), respectively. Ultrastructural studies revealed several apoptotic features such as wavy basement membrane, displaced nuclei, chromatin condensation, plasma membrane blebbing, nuclear membrane dissolution, loss of inter-Sertoli cell junctional complexes, and intercellular bridges and deformed mitochondria. A variable spectrum of sperm defects had also been visualized e.g., acrosomal deformities such as decapitation and a ring of condensed chromatin around the nuclear periphery, deformed sperm heads with a condensed nucleus, tail-elements with superfluous cytoplasm, and damage to the mitochondrial sheath and aggregation of spermatozoa within the membrane. This was further supported by TUNEL studies. Apoptotic index, epididymal sperm concentration, motility, and fertility index also revealed a significant (P?相似文献   

Therapeutic action of MK-436 (2,5-nitroimidazole) on Trypanosoma cruzi infections in mice: a parasitological, serological, histopathological, and ultrastructural study

The anti-protozoal drug MK-436 (3-(1-methyl-5-nitroimidazol-2-yl)-3a,4,5,6,7,7a-hexahydro-1,2-benzisoxazole) was found to be effective against Trypanosoma cruzi infections in mice (2 daily doses of 250 mg per kg body weight). Parasitaemia disappeared within 24 hours of treatment which was commenced during the early or late stages of acute infection. Intracellular T. cruzi parasites were also affected by the drug, ultrastructural findings showing severe cytoplasmic vacuolization and membrane alterations. Positive serological responses persisted in the majority of treated and parasitologically cured mice in the study. Cure rates varied from 72% to 100% and were similar regardless of the T. cruzi strain used (Y strain, type I; 12 SF strain, type II; or Colombian strain, type III). However, the proportion of positive serological tests and the frequency of inflammatory lesions were greatest for mice that were infected with the Colombian strain of the parasite.     

Morphometric, structural, and ultrastructural studies of tench (Tinca tinca L.) hepatocytes after copper sulfate administration.

A structural, ultrastructural, and morphometric study was made of the liver parenchyma of 12 adult tench (Tinca tinca, L.) subjected to acute experimental copper sulfate poisoning. The lesions observed were characterized by the accumulation in the cytoplasm of large amounts of hemoglobinemic pigment produced by intense hemolysis, initially in Kupffer cells and by the last stage of the experiment in hepatocytes. This process became increasingly severe, and culminated in the massive necrosis of large areas of liver parenchyma, which led to the death of tench 12 days after the start of the experiment.     

Calcium and weight: clinical studies

Data from six observational studies and three controlled trials in which calcium intake was the independent variable (and either bone mass or blood pressure the original outcome variable) have been reanalyzed to evaluate the effect of calcium intake on body weight and body fat. Analysis reveals a consistent effect of higher calcium intakes, expressed as lower body fat and/or body weight, and reduced weight gain at midlife. Similarly, studies relating nutrient intake to body composition report negative associations between calcium intake and body weight at midlife and between calcium and body fat accumulation during childhood. There is a fairly consistent effect size, with each 300 mg increment in regular calcium intake associated with approximately 1 kg less body fat in children and 2.5-3.0 kg lower body weight in adults. Taken together these data suggest that increasing calcium intake by the equivalent of two dairy servings per day could reduce the risk of overweight substantially, perhaps by as much as 70 percent.