Arterio-venous malformations of uterus - diagnostic and management dilemmas.

Keeping in mind the life-threatening consequences of curettage in cases of undiagnosed uterine arterio-venous malformation (AVM), its possibility should be considered in patients presenting with abnormal heavy uterine bleeding and negative Human Chorionic Gonadotropin (ß-hCG) values. We collected a series of cases in which the patients presented with abnormal heavy uterine bleeding, some not responding to conservative treatment. In the presence of declining or low serum ß-hCG levels and ultrasound Doppler showing increased vascularity, patients were investigated to detect the possible presence of uterine AVM. In those patients in whom angiographic confirmation of uterine AVM was made, embolisation was done and the outcome was followed. In those patients in whom hysterectomy was done the histopathogy specimen was studied for the possible cause of increased vascularity. Arterio-venous shunting seen on ultrasound does not always imply a uterine AVM and some cases can present diagnostic and management dilemmas.

Detection of single-stranded DNA in scrapie-infected brain by electron microscopy.

The nucleic acid content of enriched preparations of mitochondria/tubulofilamentous particles from normal and scrapie-infected hamster brains were examined by electron microscopy. After spreading on collodion-coated grids circular molecules of approximately 15.7 kb corresponding in size to mitochondrial DNA (mtDNA) were observed both in normal and scrapie-infected brains. In nucleic acid preparations from scrapie-infected brains multimeric mtDNA and single-stranded DNA strands of about 0.49 X 10(6) daltons were also visualized. These findings demonstrate the presence of a single-stranded DNA in scrapie-infected brains and are consistent with previous data based on enzyme digestion of nucleic acids isolated from scrapie-infected brains.

High-resolution electron microscopic analysis of the amyloid fibril in Alzheimer's disease.

Examination of brain biopsies from Alzheimer's patients by electron microscopy revealed two types of filaments in and around the argyrophile plaques. The first neurofibrillary tangles were in degenerating neuronal processes, and each twisted tubule was made up of paired helical filaments. The second type stained for amyloid and had the ultrastructural appearance of amyloid. Amyloid fibril material found in these plaques was studied by means of tilt-stage electron microscopy and compared with X-ray images of scale models of bifilar helix. The model fulfilled the structural criteria established by electron microscopy. These observations confirmed that each amyloid profile was composed of a pair of twisted tubules, each of which measured about 60 A in diameter.

A chronological study of experimental scrapie in mice.

The development of scrapie-associated particles and lesions in four regions of the brain was studied in mice over a period of 30 weeks. Characteristic tubulovesicular particles, identical to those previously described, were first found about half way through the incubation period in mice inoculated by four different routes. The particles are found in brains with scrapie and other spongiform encephalopathies; they have never been seen in other conditions, and potentially represent the infectious agent.

Pathological findings of adenine arabinoside (ARA-A) and cytarabine (ARA-C) in the treatment of herpes simplex encephalitis in rabbit model.

The injection of herpes simplex virus type 1 (HSV-1) into the vitreous body of the eye in the 18 day old albino rabbits consistently induced herpes encephalitis with 90% survival. In the untreated rabbits the lesions follow a defined anatomical pathway producing a progressive disease not dissimilar to the natural human disease in that HSV travels slowly by cell-to-cell infection of neuroglia. The effects of adenine arabinoside (ara-A) and cytarabine (ara-C) on HSV encephalitis in rabbit model were studied by starting the treatment on 4th day post-inoculation of HSV. Deaths due to toxic side effects were caused by ara-A and ara-C in 30% and 50% of animals respectively, compared with 10% in untreated animals. Neurological signs, such as head jerking, ataxia and frequent epileptiform fits, occurred in ara-A, and ara-C and untreated rabbits. Comparative histological studies of optic nerves and brains showed that ara-A and ara-C had no beneficial effect, but surprisingly enhanced the disease.

Evidence that homologous ssDNA is present in scrapie, Creutzfeldt-Jakob disease, and bovine spongiform encephalopathy.

Homogenized brain tissue from scrapie-infected hamsters and uninfected hamsters was subjected to sub-cellular fractionation to isolate nemavirus. Nucleic acid was extracted from these fractions, which also contained mitochondria. Agarose-gel electrophoresis revealed a band corresponding to the size of circular hamster mtDNA in both infected and uninfected samples, but slower migrating bands were observed only in samples from scrapie-infected brain. A single band of ssDNA corresponding to about 1.2 kb was purified by alkaline gel electrophoresis from the nucleic acid content of the enriched preparations of nemavirus. The ssDNA was synthesized into double-stranded DNA, cloned and sequenced. An unusual palindromic six base TACGTA repeat sequence was observed suggesting that 1.2 kb molecules consist of multiple copies of (TACGTA)n spaced along the length of the ssDNA with a preceding sequence TATATA. The comparison of the nucleotide sequence of the inserted DNA to the GenBank nucleotide database revealed no significant homology to other sequences. A probe prepared from the Nar 50 clone was hybridized against DNA prepared from scrapie, CJD, BSE and normal brains under various salt and temperature conditions. The probe reacted with a band of about 1.2 kb in scrapie, CJD and BSE but not with control normal DNA specimens, thereby confirming the presence of ssDNA in these SEs. The results suggest an intimate association between the presence of nemavirus particles and scrapie, CJD and BSE.

Competitive enzyme-linked immunosorbent assay for Treponema pallidum antibodies.

A competitive enzyme-linked Treponema pallidum immunosorbent assay (CETPIA) was compared with the standard serological tests for syphilis. Of 3081 serum samples submitted, 2883 gave negative results in the CETPIA and the routine screening tests. Positive results were obtained in the CETPIA and in one or more of the specific treponemal tests with 115 samples. Discrepancies in the results of the CETPIA and standard serological tests were found with 83 serum samples, most of these were attributed to biological false positive reactions in the Venereal Disease Research Laboratory (VDRL) test. CETPIA may have a role in the serological diagnosis of syphilis.

Characteristics of motile curved rods in vaginal secretions.

Motile curved rods seen in vaginal secretions have been isolated on Columbia agar supplemented with 5% human blood and vitamin K. Growth occurred anaerobically and in 5% oxygen but not in more aerobic conditions. There were two distinct groups of these organisms, distinguishable by morphology, biochemical activity and susceptibility to metronidazole. All isolates were sensitive to a wide range of antimicrobial agents, with the exception of nalidixic acid and polymyxin, but one group was resistant to metronidazole. There was little difference between the results of tests of susceptibility to aminoglycosides or to metronidazole performed in anaerobic and microaerophilic conditions. Motile curved rods were isolated from 18 of 80 patients with a clinical diagnosis of non-specific vaginitis, but from only two of 39 without the disease.

Phagocytosis and killing of bacteria in aerobic and anaerobic conditions.

Phagocytosis and intracellular killing of several facultative anaerobes were observed in aerobic and anaerobic conditions. The presence of anaerobes affected these processes. Bacteroides asaccharolyticus and B. fragilis were killed by phagocytes only at bacterial concentrations less than 1 x 10(7) cfu/ml; at higher concentrations of the anaerobes, killing of B. fragilis and concomitant facultative anaerobes was inhibited. This effect appeared to be due to an interaction, in appropriate reducing conditions, between anaerobe and serum, which allowed engulfment of organisms by phagocytes but markedly impaired intracellular killing.

An ion-exchange capture technique for routine identification of faecal viruses by electron microscopy.

Faecal specimens from 520 patients with non-bacterial, gastroenteritis were examined by electron microscopy using four methods. These were (1) a direct dip method, (2) low-speed centrifugation, (3) ultracentrifugation and (4) a calcium phosphate method. The calcium phosphate method combined with low-speed centrifugation (750 X g, 2,100 X g) was considered overall best. The calcium phosphate method makes it possible to handle a large number of faecal specimens by saving considerable time and labour.

Action of commonly used disinfectants against enteroviruses.

The virucidal effect of some of the most commonly used hospital disinfectants against Coxsackie B4, Echovirus 11, Poliovirus type 1 and Rotavirus have been evaluated. It was found that 'Chloros', 'Totacide 28' and methylated spirits were completely virucidal to all the viruses under study. 'Stericol' and 'Lysol' had a limited effect while 'Hibiscrub' and 'Savlon' had no effect at all.

Electron microscopic development of neuroglia in epiretinal portion of post-natal rabbits.

The development of epiretinal and optic nerve neuroglial cells has been studied ultrastructurally in 1-20-day post-natal rabbits. Two morphologically distinct neuroglial cells were observed, a dense "spider" type which is present from day one and a light-staining "crab" type of cell which appears on the 4th day in the epiretinal strip. "Crab" cells myelinate many axons and mature into typical dense oligodendrocytes. "Spider" cells have ultrastructural features of both astrocyte and oligodendrocyte and each cell also myelinates many axons. Many of these cells attach their processes to basement membrane of blood vessels and mature into a typical astrocyte. In 10-15-day-old animals these cells may be located at a distance of 15 micrometer or more from the axon which they enwrap. Most of these processes are sufficiently fine and tortuous to obscure the continuity in single thin sections from adult animals.

Mechanism of demyelination after HSV type I intraocular injection in rabbits.

Intraocular injection of herpes simplex virus (HSV) type I into the vitreous body of 18-day-old rabbits induced, on the 7th day post-inoculation, neurological signs with marked head jerking and atazia. Examination of semi-serial 1-micrometers thick sections of the whole lengths of right and left optic nerves and chiasma of 4--64 days post-inoculated rabbits revealed a small lesion, restricted to the medial side, which had extended 2--3 mm, during the first 4 days, along the optic nerve. Ahead of the developing lesion marked chromatin changes of neuroglial cells were noticed followed by cuffing of blood vessels, infiltration by macrophages, demyelination and remyelination. The present study indicated that demyelination occurred following the infection of the myelinating cells. It appeared that virus did not become latent and many cells survived the viral attack. Repeated episodies of viral activity caused further damage while repair did not keep pace.

Neurofibrillary tangles of paired helical filaments.

The abnormal aggregates of fibrillar material found in neurons in Alzheimer's disease, senile dementia, the Guam Parkinsonism-Dementia complex, Down's syndrome, and postencephalitic Parkinsonism were studied by means of tilt-stage electron microscopy and with X-ray images of scale models of a bifilar helix. The model fulfills the structural criteria established by electron microscopy. These studies showed that the "twisted tubule" which makes up the neurofibrillary tangle in many pathological situations is a bifilar helix made up of 130 A filaments.

A critical review of atypical cerebellum-type Creutzfeldt-Jakob disease: its relationship to "new variant" CJD and bovine spongiform encephalopathy.

Shortly after the appearance of bovine spongiform encephalopathy (BSE), Creutzfeldt-Jakob disease (CJD) was identified in young patients with nonclassical presentation such as difficulty in balancing and ataxia. The classical CJD in older patients starts with dementia. To distinguish between the two types, CJD in young persons has been termed "new variant" (nvCJD). The distinguishing features of classical CJD include initial presentation with dementia, confluent spongiform changes are very unusual in the cerebellum, and PrP plaques are rarely observed. For nvCJD, initially, difficulty with balancing and ataxia occurs, confluent spongiform changes are seen in the cerebellum, and a large number of PrP plaques are seen. The icelandic observation of sheep scrapie revealed a predominantly ataxic form of scrapie, termed Type II, rather than the itchy form termed Type I. Both types have been known to exist in Europe. Since the clinical signs of Type II scrapie in sheep with trembling and ataxia are similar to those seen in BSE and nvCJD, this suggests that Type II is the cause of BSE and nvCJD. Over 8 years, from 1989 to 1996, I examined the clinical histories of 33 CJD cases aged between the ages of 18 and 84. Six under the age of 40 and 15 over the age of 40 had leading clinical features such as difficulty in balancing and ataxia similar to those seen in the young cases classified as "nvCJD." Brains were examined from the six of 15 cases over the age of 40, which revealed similar pathology to that seen in young patients classified as "nvCJD." These findings suggest that all age groups are susceptible to the strain of the agent derived from BSE cattle.

Lingering doubts about spongiform encephalopathy and Creutzfeldt-Jakob disease.

Bovine spongiform encephalopathy (BSE) is an infectious disease and has been transmitted orally to many other animals, including humans. There is clear evidence of maternal transmission, although disagreement on the source of the BSE agent remains. The current theories link the origin of BSE to common scrapie in sheep. Twenty different strains of the scrapie agent have been isolated from sheep. A search of the literature indicates two distinct clinical syndromes in sheep, both of which have been called scrapie. I have designated these Type I (the common type), which exhibits itchiness and lose their wool, and Type II, which exhibits trembling and ataxia. Sheep inoculated with BSE develop Type II scrapie and they exhibit trembling. When cattle or mink are injected with the Type I strain, only a few will develop a clinical disease. By contrast, no clinical disease has so far been shown in cattle or mink by feeding them with Type I-infected sheep brains. However, either by injecting or feeding with the BSE strain, 100% of calves and mink develop the clinical disease. Evidence suggests that Type II is the cause of BSE. Identical clinical signs of Type II trembling are found in kuru and many of the recent cases of Creutzfeldt-Jakob disease. The BSE agent has caused spongiform encephalopathies (SEs) in domestic cats, tigers, and in some species of ruminants in zoos. The nature of the BSE agent remains unchanged when passaged through a range of species, irrespective of their genetic make up, demonstrating that variations in the host PrP gene are not a major factor in the susceptibility to the BSE agent. Since more than 85 zoo animals of many species have been diagnosed with SEs, from these studies it seems reasonable to conclude that the BSE agent can infect almost all mammalian species, including humans. For eradication of BSE and to reduce the risk of infection to humans, the development of a vaccine against BSE is suggested. Such a possibility should be fully explored.

Progression of cytomegalovirus in the rabbit following the intraocular injection of the virus.

There is growing recognition that cytomegalovirus (CMV) is one of the opportunistic infections in patients afflicted with AIDS. The purpose of the present study was to establish a chronic CMV infection of the central nervous system (CNS) in rabbits after intraocular inoculation, to evaluate the therapeutic value of the model for investigation of the effect of antiviral drugs. It was possible to establish a chronic human cytomegalovirus (HCMV) encephalitis after 14-day old rabbits were injected into the vitreous body of the eye with the HCMV. One control and two experimental rabbits were killed at 16 days and 1, 3, 6 and 9 months post-inoculation. HCMV was demonstrated from the retina, optic nerve and brain by electron microscopy. HCMV infection did not cause apparent clinical symptoms or signs in the injected animals. At the morphological level the virus-induced lesion revealed the following features: that the HCMV travels slowly along the optic nerve and crosses at the optic chiasma showing a few thickly myelinated and many demyelinated axons with astroglial scar tissue. There was no evidence of inflammatory response in the lesions as no lymphocytes, plasma cells or phagocytic cells with dead myelin or lipid contents were observed. Long term observations of HCMV inoculated rabbits showed that the intraocular lesions followed a defined anatomical pathway in the optic nerve, chiasma and brain, leading to progressive chronic disease. The rabbit model would be very suitable for the evaluation of the therapeutic value of the effect of antiviral drugs.

Efficacy of herpes vaccine and acyclovir (ACV) in a rabbit model following intraocular inoculation of herpes simplex virus.

It has been shown that injection of herpes simplex virus (HSV) type I into the vitreous body of the eye in 18-day-old albino rabbits consistently induced encephalitis. In the untreated group the lesions followed a defined anatomical pathway in the central nervous system and produced a chronic progressive disease with 95% survival. Detailed observations in the spread of HSV along the optic pathway determined the extent of damage at any given day. Some of the old rabbits developed typical herpetic lesions on nose and lips. HSV was demonstrated from these lesions by electron microscopy and also by tissue culture isolation. The combined efficacy of heat-killed herpes vaccine prepared from the same isolate and acyclovir (ACV) in this animal model was studied by starting treatment four days before or four days after the challenge. Ten animals immunised before the challenge were protected. However, immunisation after the challenge not only did not confer protection, but surprisingly, appeared to enhance the primary disease. All 10 rabbits immunised after the challenge developed weakness of the hind legs and progressed very rapidly to paralysis. ACV treatment alone did not completely abrogate the HSV infection, there appears to be reactivation of HSV which produced fresh small lesions. However, a combination of immunisation and treatment with ACV after the challenge of the 10 rabbits in the group prevented the development of weakness of the hind legs or paralysis. Detailed observations on the spread of HSV along the optic pathway revealed that pathological lesions and damage were limited in the ACV and combined treatment with ACV and vaccine group.

Motile curved bacilli. Isolation and investigation.

Motile curved bacilli seen in vaginal secretions have been isolated on Columbia agar supplemented with 5% human blood and vitamin K. Growth occurred both anaerobically and in 5% oxygen, but not under more aerobic conditions. There were two distinct groups of these organisms, distinguishable by morphology, biochemical activity, antigenic pattern and susceptibility to metronidazole. All isolates were sensitive to a wide range of antimicrobial agents, with the exception of nalidixic acid and polymyxin. One group was resistant to metronidazole.