Preexisting posterior capsule defect progressing to white mature cataract.

We present two children discovered to have a total cataract in one eye with a posterior subcapsular cataract in the other eye. Sequential photography documented rapid progression of the posterior subcapsular cataract to a preexisting posterior capsule defect and subsequently to a white, mature cataract. We propose that early intervention be considered in cases with any posterior subcapsular changes (no matter how subtle) and history of total cataract in the fellow eye, especially in any situation where loss of follow-up is likely to occur. In the event surgery is not advised, parents should be warned about possible cataract progression and the importance of regular follow-up examinations.     

Experimental studies on the comparative infectivity and pathogenicity of Streptococcus suis type 2. I. Porcine and human isolates in pigs

Piglets between 1 and 40 days of age were inoculated with varying numbers and with different isolates of Streptococcus suis type 2 by the intranasal, intravenous and subarachnoid routes. Less than 100 organisms of an isolate cultured from apparently normal pigs caused subclinical infection in 1-day-old piglets after intranasal inoculation. This infection was naturally transmitted between litter mates. Intravenous inoculation of a similar isolate in 7-week-old pigs resulted in a sub-clinical bacteraemia in 3 of 8 piglets. One other piglet developed a bacteraemia 7 days after inoculation and concurrently developed signs of lameness and nervous dysfunction. Ten piglets were inoculated by the subarachnoid route with a porcine isolate and two with an isolate from a person with clinical disease. Only the latter two pigs developed the classical signs of nervous disease associated with infection by S. suis type 2. It is concluded that strains of S. suis type 2, of varying pathogenicity for both pigs and man, are endemic in New Zealand. It is suggested that the occurrence of disease is associated with both exposure to a pathogenic strain and other, as yet undetermined, secondary factors.     

Effects of induced hypotension during experimental vasospasm: a neurological, electrophysiological, and pathological analysis

Vasospasm of the vertebrobasilar system was induced in seven dogs by the intracisternal injection of autologous blood. Somatosensory and brain stem auditory evoked potentials were recorded before and after the induction of angiographically confirmed vasospasm. Additionally, somatosensory evoked potentials were monitored during graded hypotension to 40 mm Hg. There was no significant alteration in the evoked potentials by vasospasm or hypotension. Detailed clinical examination and postmortem histopathological studies did not demonstrate any focal neurological deficit or infarction attributable to vasospasm. Previous studies have noted close correlations between decreased cerebral blood flow and evoked potential alterations. Induced hypotension to a mean arterial pressure of 40 mm Hg in the presence of documented vasospasm was not sufficient to cause evoked potential changes, focal neurological deficit, or pathological evidence of infarction in the canine model.     

ORAL-MOTOR DYSFUNCTION AND FEEDING DISORDERS OF INFANTS WITH TURNER SYNDROME

The oral-motor function of 10 infants with Turner syndrome and their age- and sex-matched controls were assessed during feeding. In addition to well-recognised dysmorphic features, including oral anomalies and high-arched palates, index infants had marked hypotonia of the cheeks and lips, dysfunctional tongue movements and poorly developed chewing skills. Their meal-times were significantly shorter than those of the controls and they weighed significantly less at six, 12 and 15 months. All mothers of infants with Turner syndrome complained of difficulties feeding their children and these problems often had been present since birth.     

Physician assistants in academic radiology: the harborview experience

We describe a model of how physician assistants can be used in an academic medical center to expand radiologist productivity, and to enhance the departmental academic and educational missions. At Harborview Medical Center, following a training program and graduated responsibility under supervision, physician assistants provide initial interpretation of radiology studies, consultation to referring physicians, and perform less complicated interventional procedures. Acceptance of physician assistants by the radiologists, radiology residents, and referring physicians has been high. Although the impact of physician assistants on departmental clinical productivity is difficult to measure, our data suggest that radiologists are more efficient when physician assistants are assigned to service, both in terms of numbers of studies interpreted, and timeliness of reporting and billing. As a result of the success of our program, we believe that physician assistants can have an important role in radiology practice.     

Experimental studies on the comparative infectivity and pathogenicity of Streptococcus suis type 2. II. Porcine and human isolates in laboratory animals

Mice, rats, guinea-pigs and rabbits were inoculated with isolates of Streptococcus suis type 2. An isolate cultured from the tonsils of a healthy pig, produced disease in rabbits after intravenous inoculation but not in mice, rats or guinea-pigs. An isolate of S. suis type 2, that was pathogenic for pigs and had been cultured from a human patient with clinical disease, produced signs of neurological disease in mice, rats and rabbits following intravenous inoculation. There was an apparent dose response in mice with 31% of mice receiving more than 10(6) organisms developing clinical disease, whilst mice receiving less than this did not develop disease. There were no detectable histopathological lesions in the brains or meninges of mice with nervous signs. It is proposed that the disease in mice may mimic that reported in humans and that mice may be a useful indicator species for determining the virulence of isolates cultured from pigs.     

Synthesis of DNA by the spleens of germ-free mice during the primary response to sheep red cells

The mitotic activity of the spleens of non-immunized germ-free (GF) mice was less than in similar specific pathogen-free (SPF) animals. No evidence of germinal center activity was noted in these GF mouse spleens before challenge with sheep erythrocytes (SRC). These centers only began to develop 4 days after immunization and were not fully developed before 8 days. In control SPF mice, the spleens showed very few germinal centers which were small in size, but they showed the same pattern of evolution as in similarly immunized GF mice. The changes in the red pulp, characterized by the development of clusters of nuclei labeled with [³H]thymidine, followed closely the development of plaqueforming cells (PFC). The numbers of direct PFC reached the same peak level in GF and SPF mice on day 4 of the response to SRC, but were not so well sustained in the former animals after this time. Indirect PFC were much lower in the spleens of GF mice than in SPF animals. The pattern and degree of increase of DNA synthesis in the spleen of GF and SPF mice following immunization with SRC differed from and was less than that of mice reared in less clean conditions. Increased DNA synthesis occurred very soon after injection of SRC (6 to 24 h) and the increase was sustained for 4 days without further significant rise and then declined. Autoradiographs of the spleen of immunized GF mice given [³H]thymidine showed that the first increase of labeled nuclei in the white pulp occurred around the central arterioles as early as 6 h after SRC. This was followed by increased labeling in the mantle layer of the white pulp and the characteristic pattern of germinal center labeling developed after 4 days. Increased labeling of nuclei developed in the red pulp as early as in the white pulp, while the subcapsular and trabecular areas showed high labeling indices even in the spleens of non-immunized controls. The ratio of labeling index/mitotic index which is governed by the respective durations of DNA synthesis and mitosis in those cells in division cycle, varied between 10 and 280 in different areas of the spleen. This indicated a vast excess of cells synthesising DNA in relation to the numbers of dividing cells actually present in the spleens of these mice.     

APOE is a potential modifier gene in an autosomal dominant form of frontotemporal dementia (IBMPFD).

PURPOSE: Inclusion-body myopathy, Paget's disease of bone and frontotemporal dementia is an adult-onset autosomal dominant illness (IBMPFD) caused by mutations in the valosin-containing protein (VCP) on chromosome 9p21.1-p12. The penetrance of the gene is 82% for myopathy, 49% for Paget's disease, but may be as low as 30% for frontotemporal dementia. Modifier genes could account for decreased frontotemporal dementia penetrance. In this study apolipoprotein-E (APOE) was evaluated for this role in IBMPFD families based on its known modifier effect in Alzheimer's disease. METHODS: From a database of 231 members of 15 families, 174 had APOE genotype available for analysis. Logistic regressions on APOE genotype and frontotemporal dementia were performed, using appropriate covariates. RESULTS AND CONCLUSION: FTD was associated with APOE 4 genotype (P=0.0002), myopathy (P=0.0006), and age (P=0.01), but not microtubule associated protein tau (MAPT) H2 haplotype (P=0.5) or gender (0.09) after adjustment for membership in pedigrees with at least one APOE 4 genotype. These data suggest a potential link between APOE 4 genotype and the specific form of frontotemporal dementia found in IBMPFD. The molecular basis of this link bears further investigation. We did not observe an association of frontotemporal dementia and H2 MAPT haplotype.