Infectious diarrhea in tourists staying in a resort hotel

An outbreak of infectious diarrhea with 70 laboratory-confirmed cases (58 with Giardia lamblia) and 107 probable cases occurred in U.K. tourists who stayed in a hotel in Greece. After a cluster of six cases in persons who had stayed at the hotel was reported, the Communicable Disease Surveillance Centre began active case ascertainment. This outbreak illustrates the value of an approach to surveillance that integrates routine surveillance data with active case ascertainment.

Factors regulating pS2-reporter gene expression in MCF-7 breast cancer cell line

From the estrogen receptor containing breast cancer cell line MCF-7, several genes were shown to be hormone-inducible. The regulatory components involved in transcriptional regulation of one of them, the pS2 gene, was determined using 1100 bp of its 5'-flanking region to drive the luciferase reporter gene in transiently transfected cells. MCF-7 breast cancer cells expressed 4-times as much luciferase compared to the pancreatic cell line PANG-I, that has ceased endogenous pS2 expression, as well as the colonic cell line CX-1. In MCF-7, pS2-triggered reporter gene expression is greatly enhanced by the tumor promoter TPA, and, to some extend by EGF, demonstrating that pS2 gene expression is due to specific trans-activating factors present in MCF-7, but not in PANG-I or CX-1. Cotransfection by estrogen receptor stimulated expression 10-fold, and combination with TPA had a synergistic effect, inducing expression 100-fold. EGF and estrogen receptor also work synergistically. The enhancing effect was abolished by deleting cis-acting regulatory sequences near the estrogen responsive element, suggesting that the corresponding regulatory factors may physically interact. This luciferase reporter gene assay quickly and conveniently tests the responsiveness to exogenous stimuli and the presence of specific transcription factors in different tumor cell lines.

The effects of maternal aerobic exercise on human placental development: placental volumetric composition and surface areas

The histomorphometry of term placentae from women who exercised regularly throughout either the first half or all of pregnancy was compared to that of placentae from matched controls to determine if regular exercise during pregnancy produced histomorphometric evidence of altered development and transport capacity. Conventional stereological techniques were used to estimate placental volumetric composition, surface areas, and villous and vascular configurations in the three groups. Exercise confined to early pregnancy increased the parenchymal component of the placenta, total vascular volume and site-specific capillary volume and surface area. Exercise throughout pregnancy increased these and multiple other histomorphometric parameters associated with the rate of placental perfusion and transfer function. However, significant changes were confined to villi > 80 microns in diameter. The localization of both the timing of the stimulus and the anatomical sites affected indicates that regular, sustained exercise modifies placental development primarily in early and mid-pregnancy. We speculate that the lack of significant changes in the structure and configuration of the smaller villi indicates that other adaptive mechanisms, such as increased rates of placental blood flow, must be well developed by the latter portion of the mid-trimester and adequately maintain fetal oxygenation and substrate delivery throughout the third trimester.

Abnormal somatosensory evoked potentials in patients with classic galactosemia: correlation with neurologic outcome

In classic galactosemia, long-term neurologic sequelae can include low cognitive functioning and a curious neurologic syndrome with tremors, dysmetria, and ataxia. An abnormal white-matter signal on cerebral magnetic resonance imaging (MRI) is present in almost all patients; some have mild cerebral or cerebellar atrophy and focal white-matter lesions. The present study was undertaken to assess the integrity of myelinated pathways by recording somatosensory evoked potentials. Results were correlated with age at diagnosis, severity of illness, age at evoked potentials, neurologic examination, MRI studies and cognitive outcome as measured by the Woodcock-Johnson Revised Standard Cognitive Battery. Evoked potentials were abnormal in 17 (28%) of 60 patients who had median nerve, and 26 (77%) of 34 patients who had posterior tibial nerve studies. Abnormalities of the central rather than the peripheral nervous system were most common. Evoked potentials correlated with severity of presenting symptoms (P = .011), age at evoked potential testing (P = .029), and presence of focal white-matter lesions on MRI (P = .049). Results of neurophysiologic testing showed no correlation with the Woodcock-Johnson Battery. Patients with classic galactosemia may have abnormal conduction along myelinated pathways that is associated with other central deficits. Myelin, which contains galactose, may be adversely affected in this inborn error of metabolism.

Short-latency somatosensory evoked potentials correlate with the severity of the neurological deficit and sensory abnormalities following cerebral ischemia

Short-latency somatosensory evoked potentials (SSEPs) were studied in 49 patients who had suffered hemispheric or thalamic ischemia, including 6 patients with transient ischemic attacks (TIAs) and 3 patients with reversible ischemic neurological deficits (RINDs). SSEPs were abnormal in 30 patients (61%). SSEP abnormalities correlated with the presence of sensory deficit and the degree of neurological deficit. SSEPs were normal following TIA but were abnormal in 2 of 3 patients with RINDs. SSEPs were abnormal in some patients without sensory deficits suggesting that sensory pathways may be affected when clinically inapparent.

Bromocriptine treatment of prolactin-secreting tumors: surgical implications

Ten of 19 patients with Stage III-IV prolactin-secreting tumors experienced significant reduction in the size of the tumor when treated with therapeutic doses of bromocriptine. Those tumors that responded favorably to preoperative pharmacological manipulation were found to have an improved surgical cure rate. These preliminary data suggest that a preoperative effort to reduce the size of large prolactin-secreting tumors may result in significant improvement of our surgical ventures.

Natural history of microprolactinomas: six-year follow-up

A 6-year follow-up of patients harboring microprolactinomas suggests that few patients (3 of 27) demonstrate significant growth of their tumor during this time. The major hazard for such patients who are not treated seems to be their risk for the development of premature osteoporosis in the face of sustained hyperprolactinemia. The risks of this complication may exceed the risks of early surgical intervention in selected patients. This short term risk of tumor growth (about 10%) must be weighed in the decision about therapeutic endeavors.