Myocardial perfusion imaging with technetium-99m sestamibi SPECT in the evaluation of coronary artery disease

Technetium-99m hexakis-2-methoxy-isobutyl-isonitrile(^99mTc sestamibi) has been used for myocardial perfusion imaging in the evaluation of coronary artery disease (CAD) since 1990. The experience of its use in an Asian population with and without previous myocardial infarction (Ml), diabetes mellitus (DM), hypertension (HPT) and collateral circulation (COL) is reported. One hundred and thirty-nine patients who underwent treadmill exercise testing with ^99mTc sestamibi single photon emission computed tomography (SPECT) and coronary angiogram were studied. The overall sensitivity for the detection of CAD was 91.0% and specificity was 64.7%. For patients without previous myocardial infarction, the sensitivity was 83.8% and specificity was 83.3%. Patients with COL had a higher sensitivity while those with HPT had a lower specificity. Sensitivity was higher in patients with multi-vessel disease (MVD) than single vessel disease (SVD). The overall detection for individual artery stenosis was 74.1% with a specificity of 73.1 %. Amongst the three major coronary arteries, sensitivity was highest for the right coronary artery and specificity was highest for the left circumflex artery. Specificity was higher in patients without MI or COL. We found that the agreement between ^99mTc sestamibi SPECT and coronary angiogram for the extent of CAD was only 52.5%. The concordance rate was higher for patients with MVD than SVD. It is concluded that ^99mTc sestamibi SPECT is a sensitive and specific test for the detection of CAD and localization of disease to individual coronary arteries in our patients with some differences in the subgroups. Agreement between coronary angiogram and ^99mTc sestamibi for the extent of coronary artery disease was also satisfactory.     

Endometritis and acute salpingitis associated with Chlamydia trachomatis and herpes simplex virus type two

A patient who had endometritis confirmed by endometrial biopsy and acute salpingitis confirmed by laparoscopy is reported. Chlamydia trachomatis and herpes simplex virus type two were isolated from the endometrial cavity and the fallopian tube. The histopathologic findings of the endometritis were similar to those frequently seen in chronic chlamydial eye disease or chlamydial cervicitis.     

Prevalence and manifestations of endometritis among women with cervicitis

Thirty-five women referred from a clinic treating sexually transmitted diseases, because of suspected cervicitis, were studied for the presence of endometritis by transcervical endometrial biopsies and cervical and endometrial cultures. Fourteen (40%) of the patients had histologic evidence of endometritis. Findings that significantly correlated with endometritis included a history of intermenstrual vaginal bleeding, the presence of Chlamydia trachomatis, Neisseria gonorrhoeae, or Streptococcus agalactiae in the cervix, and the presence of serum antibodies to C. trachomatis or to Mycoplasma hominis.     

Effect of alendronate on periprosthetic bone loss after total knee arthroplasty: a one-year,randomized, controlled trial of 19 patients

Undesired bone loss around implants is considered to occur mainly because of a stress-shielding phenomenon. Bone surrounding the total knee arthroplasty (TKA) adjusts its mineral density and structure to meet new mechanical demands. Immobilization, in combination with local operative trauma to the bone and soft tissues, has an additional impact on bone loss. The clinical survival of TKA is associated with the quality and quantity of the surrounding bone environment. Poor bone quality and quantity may predispose to aseptic implant loosening and periprosthetic fractures. We investigated the efficacy of oral bisphosphonate (alendronate, Fosamax) with calcium (Calcichew) for the inhibition of early bone mineral density (BMD) loss after TKA in a prospective, randomized, one-year follow-up study. Periprosthetic BMD changes were measured with fan-beam dual-energy X-ray absorptiometry (DXA) in 19 patients with knee osteoarthrosis. Patients (n = 8) treated with 10 mg alendronate and 500 mg calcium daily maintained distal femoral BMD values close to the baseline values (P > 0.04), while patients receiving only 500 mg of calcium daily (n = 11) showed significant bone loss during the one-year follow-up (P < 0.015). The treatment groups differed significantly in metaphyseal anterior, posterior, diaphyseal, and metaphyseal total regions of interest (ROIs) (repeated measures ANOVA analyses, P = 0.019, P = 0.010, P = 0.022, and P = 0.024, respectively). Our results indicate that oral alendronate reduces early postoperative periprosthetic bone loss significantly. This therapeutic strategy may improve the results and longevity of primary total knee arthroplasties.     

BDNF regulates the expression of fragile X mental retardation protein mRNA in the hippocampus

Both fragile X mental retardation protein (FMRP) and brain-derived neurotrophic factor (BDNF) are implicated in the maturation of neurons and in the higher cognitive functions. We have investigated whether FMRP and BDNF are reciprocally regulated in neurons. Exposure of cultured hippocampal neurons to BDNF, but not to NT-3, reduced FMR1 mRNA levels to 84.8% of control at 4 h and the levels were back to baseline by 24 h or 4 days. Furthermore, expression of FMR1 mRNA was reduced (82.4% of control) in vivo in the hippocampus of transgenic mice overexpressing TrkB receptors, and a small but significant (5.1%) decrease was also detected in FMRP protein levels. In contrast, the expression patterns of BDNF and TrkB mRNAs were not altered in FMRP-deficient mice compared to wild-type mice. Our data provide evidence that BDNF via TrkB signaling decreases FMRP expression and suggest a role for FMRP in BDNF-induced synaptic plasticity.     

Screening for lung cancer

Screening for lung cancer serves to prevent deaths from this disease insofar as earlier resections are associated with higher rates of cure. There is good reason to believe that this is the case: in stage I, the 5-year survival rate with resection is 70%, whereas without resection the corresponding rate is only 10%. Before this evidence emerged, various authoritative organizations and agencies in North America advised against screening for lung cancer on the grounds of the results of several RCTs. As for CXR, I argue that the study results are consistent with up to 40% reduction in the fatality rate. Moreover, modern helical CT screening provides for detecting much smaller tumors than were detected in those studies. It is time to revoke the conclusion that screening for lung cancer does not serve to prevent deaths from this disease, and to quantify the usefulness of CT screening in particular. As for the requisite research, the prevailing orthodoxy has it that RCTs are to be used, but I argue that more meaningful results are obtainable, more rapidly and much less expensively, by the use of noncomparative (and hence unrandomized) studies.     

Localization of M2 muscarinic receptor protein in parvalbumin and calretinin containing cells of the adult rat entorhinal cortex using two complementary methods

We investigated parvalbumin (PV) and calretinin (CR) containing interneurons in the rat entorhinal cortex. RNA amplification following single cell dissection of immunohistochemically labeled cells from layers II to VI revealed that PV cells, in contrast to CR cells, express the m2 muscarinic receptor (M2AchR) protein. Double immunostaining to confirm the results of RNA amplification indicated that the majority of PV cells contain M2AchR protein, whereas only a small proportion of CR cells do. In contrast, a large number of layer I CR cells, which are mostly Cajal-Retzius cells, were positive for M2AchR. RNA amplification following dissection of these cells also revealed that they contain the M2AchR protein. These findings emphasize that there are significant differences in the expression of different proteins, even among similar neuronal types in the same brain region. This highlights the importance of accurately collecting single cells, and knowledge of anatomical details in molecular biological studies.     

Enhanced cerebral substrate pools in the fetus and neonate of the diabetic canine mother

Energy stores and intermediates of carbohydrate metabolism were investigated in the freeze-clamped cerebral cortex of the fetus and fasted neonate born to a diabetic canine mother. Prior studies in these same pups demonstrated circulating hyperinsulinemia, depressed free fatty acid levels, and attenuated gluconeogenesis. Hepatic and muscle tissue also demonstrated augmented levels of glycogen, triglycerides, and amino acids. In the present investigation, cerebral tissue from these same pups of diabetic mothers also demonstrated enhanced fetal cerebral glucose and glycogen content. After 24 h of neonatal fasting, cerebral glycogen content declined to values lower than in control pups. Cerebral cortical levels of glucose-6-phosphate, fructose-6-phosphate, lactate, citrate, alpha-ketoglutarate, and malate were not altered, while oxaloacetate was higher at 3 and 9 h and fructose-1,6-diphosphate was higher at 9 and 24 h in the IDM pups. Adenine nucleotide levels and the energy charge were equivalent to those in control pups at each time interval. In contrast, cerebral cortical amino acids of the glutamate group were enhanced in the fetus or neonate of the diabetic mother. Cerebral cortical alanine was increased from 3 to 24 h while aspartate and glutamate were augmented in the fetus and fasted IDM newborn pup. Glutamine was increased at 6 and 24 h, while gamma-aminobutyrate was elevated in the fetus. Cerebral ammonia concentration was not altered. The augmented stores of cerebral carbohydrate and amino acid pools in the fetus and neonate after maternal canine diabetes may serve as oxidizable substrates for the brain during periods of attenuated systemic fuel availability.(ABSTRACT TRUNCATED AT 250 WORDS)