Leydig cell tumor induced hypercalcemia in the Fischer rat: morphometric and histochemical evidence for a humoral factor that activates osteoclasts.

A nonmetastatic, transplantable Leydig cell tumor of Fischer rats causes hypercalcemia in the host animals. The tumor's effects on long bones were studied with histochemical and morphometric methods. Small viable fragments of the tumor (about 1 cu mm) were transplanted into 59 Fischer rats. After 2 weeks, when the animals were sacrificed, the tumors weighed 13.9 +/- 4.8 gr (SD), and the animals had lost a mean of 10.1 g of weight. Compared with 16 normal control rats (mean weight gain of 9.5 g), the tumor-bearing rats showed: 1) a reduction in the volume of trabecular bone, which correlated well with the weight of the tumor; 2) a significant narrowing of the epiphyseal plate cartilage; 3) a diminution in the number of marrow fat cells, which in most tumor-bearing rats were totally absent; 4) an increase in the number of osteoclasts many of which were mononuclear and had to be identified with the aid of a histochemical reaction for acid phosphatase; 5) a great expansion of the marrow vascular channels that maintained an endothelial lining. Since there is no metastasis of the tumor cells, the effects of the tumor are presumably mediated by a humoral factor that activates existing osteoclasts and induces monocytes to differentiate into osteoclasts.     

Fetal sex-related differences in maternal serum alpha-fetoprotein during the second trimester of pregnancy

In an analysis of data gathered from routine maternal serum alpha-fetoprotein screening, we determined that the sex of the fetus is significantly correlated with differences in maternal serum alpha-fetoprotein concentration during the second trimester of pregnancy. Between the fifteenth and nineteenth gestational weeks, the mean maternal serum alpha-fetoprotein level is significantly higher for the male fetus than for the female fetus. There was no difference, however, in the rate of increase in maternal serum alpha-fetoprotein concentration with time between male and female fetuses during the weeks of gestation that were studied. No apparent cause for these observations has been demonstrated.     

Lactose intolerance among Mexican Americans.

Thirty-three Mexican Americans between the ages of 9 and 60 were interviewed and tested for lactose intolerance. The participants of the study included 16 children and 17 persons not related by birth, including the parents of the children. Determination of lactose intolerance was based on a rise of less than 25mg/100 ml of blood glucose as measured by an Ames Dextrostix/Reflectance Meter following consumption of a lactose load. Forty-seven percent of the 17 nonrelated Mexican Americans were lactose intolerant. There was a marked relationship between low rise in blood glucose and symptoms of diarrhea, flatulence, and distention. Sixteen children from four families had an incidence of 50 per cent intolerance. The findings of intolerance in two successive generations of three families and in both sexes of the families adds support to the contention that lactose intolerance has a genetic basis, without sex predilection.     

Obesity, cardiometabolic syndrome, and chronic kidney disease: the weight of the evidence

The epidemic of obesity experienced in both industrialized and nonindustrialized countries largely accounts for the increase in the prevalence of the cardiometabolic syndrome (CMS). Obesity and the CMS significantly increase the risk for cardiovascular disease (CVD) and chronic kidney disease (CKD). Multiple abnormalities that can lead to kidney injury have been identified in overweight and obese people, including insulin resistance, compensatory hyperinsulinemia, inappropriate activation of the renin-angiotensin-aldosterone system and increased oxidative stress, endoplasmic reticulum stress, coagulability, and impaired fibrinolysis. The combined effects of these conditions induce in the kidneys impaired pressure natriuresis, glomerular hypertension, endothelial dysfunction, and vasoconstriction, as well as matrix proliferation and expansion. Among the consequences are microalbuminuria, now known to be a surrogate of diffuse endothelial dysfunction as well as a predictor of CVD, and CKD. Diet and regular physical activity are the cornerstones of weight management, and they add to currently available pharmacologic agents and bariatric surgery. The understanding of the pathophysiology of obesity/CMS helps to explain the benefits of agents that improve insulin sensitivity, control inflammation, and block the renin-angiotensin-aldosterone system. The increasing prevalence of obesity and CMS contribute to the growing frequency of CKD and demands the development of multifactorial strategies directed at identifying people at risk, as well as preventing excessive weight gain and its deleterious consequences.     

Anaphylactic and allergic reactions during double-contrast studies: is glucagon or barium suspension the allergen?

The authors report three anaphylactic reactions and one allergic reaction during double-contrast studies using glucagon. Symptoms included hives, periorbital edema, and breathing difficulties. Studies performed were three double-contrast barium enemas and one double-contrast upper gastrointestinal series. Glucagon injection and/or an additive in barium suspension are suspected as the likely causes. The allergic potential of glucagon injection, which is not generally appreciated, is reviewed.     

Computed tomography in the diagnosis of congenital cytomegalic inclusion disease

We present two cases of congenital CID, one in a 4-month-old male infant and the other in a 6-week-old male infant. The diagnoses were confirmed by means of computed tomography, cultures, and serologic methods. The relatively noninvasive character of CT makes it an ideal diagnostic method in the neonate. With the improved visualization afforded by CT, specificity on radiographic grounds alone may become possible.     

Photorhabdus asymbiotica, a pathogen emerging on two continents that proves that there is no substitute for a well-trained clinical microbiologist

A 54-year-old ranch hand presented to the emergency room with an alleged spider bite and multiple abscesses. Both wound and blood cultures grew Photorhabdus asymbiotica, an enteric gram-negative rod that was initially misidentified by the hospital's rapid identification system. Clinical laboratories should be aware of the limitations of their rapid identification systems and always use them as an adjunct to analysis of morphological and phenotypic traits.     

Methodologic issues in clinical trials for prevention or risk reduction in osteoarthritis

The design and execution of prevention trials for OA have methodological issues that are distinct from trials designed to impact prevalent disease. Disease definitions and their precise and sensitive measurement, identification of high-risk populations, the nature of the intervention (pharmaceutical, nutraceutical, behavioral) and its potential pleiotropic impacts on other organ systems are critical to consider. Because prevention trials may be prolonged, close attention to concomitant life changes and co-morbidities, adherence and participant retention in the trial is of primary importance, as is recognition of the potential for "preventive misconception" and "behavioral disinhibition" to affect the ability of the trial to show an effect of the intervention under study. None of these potential pitfalls precludes a successful and scientifically rigorous process and outcome. As technology improves the means to measure and predict the OA process and its clinical consequences, it will be increasingly possible to screen individuals for high-risk phenotypes, combining clinical factors with information from imaging, genetic, metabolic and other biomarkers and to impact this high-risk condition to avoid or delay OA both structurally and symptomatically.     

Metabolic syndrome in the elderly

The prevalence of metabolic syndrome is increasing worldwide, especially among the elderly. Due to multiple age-related physiologic mechanisms, the elderly are at increased risk of developing intra-abdominal obesity and the metabolic syndrome, including nonalcoholic steatohepatitis. Metabolic syndrome consists of obesity, insulin resistance, dyslipidemia, and hypertension leading to increased risk of cardiovascular disease (CVD) and renal events. With the future population dynamics, the metabolic syndrome should be emphasized among the health care field, researchers, and clinicians. Without proactive and preventative efforts, elderly patients and the health care system will likely experience an epidemic of the metabolic syndrome and the associated CVD.