Significance of fibrils in the formation of the Kimmelstiel-Wilson nodule

Summary The pathogenesis of the nodular lesion in diabetic glomerulosclerosis is described in association with fibrils. Thirteen diabetic patients with glomerular nodular lesions and 9 diabetics without the nodules were examined by electron microscopy using periodic acid-thio-carbohydrazide-silver proteinate staining. In cases of nodular glomerulosclerosis, abundant fibrillar structures mixed with electron-dense material were detected within the nodule and the mesangial matrix. They were also occasionally observed along the subendothelial space of the glomerular capillary walls. On the cross-section, these fibrils, including the lucent periphery, were 34 nm wide. Immunohistologically, collagen V and collagen VI were detected in nodular lesions. In contrast, in cases of the diffuse type of glomerulosclerosis, the widened mesangium was composed of dense material, which resembled the original mesangial matrix. The above fibrils were not detected in the mesangium. These findings suggest that the accumulation of the peculiar fibrils in the glomerular mesangium is a major pathogenic factor in the formation of Kimmelstiel-Wilson nodules.     

Human papovavirus in a routine urine specimen of a four-year-old boy

Cellular changes produced by viruses can be readily identified using light microscopy and Papanicolaou stain of a fixed specimen. These findings can then be confirmed by viral culture and/or electron microscopy studies. Human polyomavirus, common in transplant recipients or otherwise immunocompromised patients, is one virus that can be identified using these methods. The following is a case study of a 4-yr-old boy with no known immune impairment who exhibited human papovavirus (polyomavirus) on a routine urine examination. The diagnosis was confirmed by electron microscopy.     

Disseminated histoplasmosis in a non-immunocompromised host

Histoplasma infections in Europe are rare, and acute disseminated histoplasmosis has only been observed in immunocompromised persons. We describe a case of acute disseminated histoplasmosis in a young, nonimmunocompromised European woman. The probable source of infection was Sri Lanka or the Maldives. At presentation she was severely ill with fever, lymphadenopathy, anemia, thrombocytopenia, hepatosplenomegaly, and polyserositis. Histologically, myelofibrosis and osteosclerosis were observed with extramedullary hematopoiesis. Histoplasma capsulatum yeasts were detected in bone marrow trephine biopsy by methenamine silver staining. Treatment with conventional and liposomal amphotericin B and subsequent itraconazole led to rapid and complete recovery.Abbreviations He Histoplasma capsulatum - AIDS acquired immunodeficiency syndrome - HIV human immunodeficiency virus     

203例幽门螺杆菌相关性胃病的临床病理诊断分析

目的:探讨基层医院胃、十二指肠疾病幽门螺杆菌(HP)感染情况,检测方法及HP感染性胃病的临床病理形态特点。方法:采用北京同仁医院消化内科刘宾等提供的改良胃镜下HP感染的可视化诊断和Giemsa染色的HP形态学病理诊断方法,对203例上胃肠道疾病患者进行检测,并对其胃粘膜进行组织形态观察。结果:改良胃镜下HP的可视化诊断阳性率为96.55％,Giemsa染色病理诊断阳性率为95.07％,改良胃镜下HP感染的可视化诊断与病理诊断符合率为98.47％。HP感染胃粘膜有特征性组织形态改变。结论:改良胃镜下HP感染的可视化诊断及Giemsa染色HP形态学病理诊断相结合运用于胃、十二脂肠疾病的HP检测,适合普通基层医院采用。HP感染胃粘膜有特征性组织形态改变。     

Vitamin A status of socio-economically backward children

A comprehensive survey was carried out to asses the Vitamin A status of pre-school (0–6 yrs.) and school age (6–12 yrs.) children of socio-economically backward families from slums of Bombay and its suburbs. The Vitamin A, protein, calories and iron from the rice and dal based diet was found to be below recommended dietary allowances (RDA). Among the 1956 children surveyed 20% of the children showed low (<20 μg/dl) serum vitamin A levels. 4.8% of the children were suffering from one or the other signs of Vitamin A deficiency. Rose Bengal stain test (RBST) and conjuctival impression cytology (CIC) indicted the signs of mild conjuctival xerosis and of early epithelial changes which were correlated with serum vitamin A levels. Serum iron, PCV, Hb and RBC levels were below normal. The anthropometric measurements of these children were below 50th percentile of Indian Council of Medical Research (ICMR) standards. Due to lack of proper nutrition, the overall growth of children is either retarded or not upto the standard levels as was noted in majority of the children.     

The effect of the illumination time when treating port-wine stains

This paper reports the electron microscopy results obtained from two patients who were treated with 5 W of yellow (578 nm) light from a copper vapour laser with an illumination time of 3.6 ms and a 0.3 mm spot diameter. The endpoint of treatment was transient blanching. Following treatment, erythema was observed. There was minimal damage to the epidermis and non-vascular tissue such as the nerve fibres. There was severe damage to the endothelial cells of the ectatic vessels. Twenty-four hours after treatment, platelet activation and collagen were present, indicating that these vessels were no longer viable. Theoretical calculations are used to determine the flow of heat within and away from a 50m diameter vessel. From this, heating of the entire vessel is shown to occur with illumination times of 4 ms, with minimal heating of the non-vascular tissue. Shorter illuminations do not heat the entire vessel, while the use of longer illumination times will cause excessive damage to the surrounding non-vascular tissue. Illumination times close to 4 ms must be regarded as optimal.     

Laser energy threshold for thermal vascular injury in a port-wine stain skin model

Monte Carlo simulation of laser energy deposition in a port-wine stain (PWS) skin model and numerical solution of the thermal diffusion equation have been used to calculate threshold energies for thermal injury of PWS blood vessels for different vessel sizes and laser pulse durations. It has been assumed that an average vessel temperature rise of 65 C causes thermal injury to the blood vessel. The result is that for a certain combination of wavelength, pulse duration and incident energy density, only a limited range of blood vessel sizes can be injured optimally. Higher energy densities are required to injure smaller vessels with the same pulse duration, spot size and wavelength. This gives support to the mechanisms of selective photothermolysis suggested previously by Anderson and Parrish, although their model was based on the cooling behaviour of instantaneously heated vessels. The authors hypothesize that different laser parameter settings that match the individual PWS vessel anatomy during treatment will be used in the future, instead of many treatments with the same laser parameters. This could lead to less treatment sessions and to an improved predictability of clinical results.     

Likelihood ratios for mixed stains when the number of donors cannot be agreed

Suppose that part of the prosecution's evidence in some crime case is analysis of a blood stain, and that the traits E discovered in the stain suggest multiple donors. Then the prosecution will probably allege some specific inculpatory hypothesis H₀ about the sources of the stain, and P {E | H₀} can be calculated. It is desirable to use this as the numerator of a likelihood ratio. However, in general the obvious denominator P {E | H₀} cannot be calculated, so unless the defense is sufficiently obliging as to stipulate to a specific choice among the potentially infinite number of more or less exculpatory alternative hypotheses, the desired likelihood ratio can't be evaluated. We show that nonetheless, in most cases there is an adequate inequality.     

Experience with the PCR-based HLA-DQα DNA typing system in routine forensic casework

Summary The results of HLA-DQ typing from 42 routine forensic cases using the polymerase chain reaction (PCR) were analyzed regarding the reliability, discrimination efficiency and informative value of this system in a given case. The cases included stain typing from a variety of different substrates, i.e. blood and semen stains, mixed body fluids, single hairs, cigarette butts, material from fingernail scratches, as well as identification and paternity cases on postmortem and fixed tissue. A total of 125 individual stain and tissue samples were included. PCR amplification was achieved in 70% of these samples. In cases with mixed body fluids, e.g. sperm and vaginal cells from rape cases, DQ typing was always carried out successfully. However, only approx. 42% of all samples that could be typed were relevant regarding the inclusion or exclusion of a suspect. This was mostly due to the limited number of alleles that can be typed at the HLA-DQ locus or to the fact that the stain or hair samples did not originate from the perpetrator, but from the victim or from other persons not related to the crime.