A hypothesis test for the end of a common source outbreak

The objective of this article is to develop a hypothesis-testing procedure to determine whether a common source outbreak has ended. We consider the case when neither the calendar date of exposure to the pathogen nor the exact incubation period distribution is known. The hypothesis-testing procedure is based on the spacings between ordered calendar dates of disease onset of the cases. A simulation study was performed to evaluate the robustness of the methods to various models for the incubation period of infectious diseases. We investigated the impact of multiple testing on the overall outbreak-wise type I error probability. We derive expressions for the outbreak-wise type I error probability and show that multiple testing has minimal effect on inflating that error probability. The results are discussed in the context of the 2001 U.S. anthrax outbreak.     

A common source of error in pH measurements.

Glass-electrode assemblies in which the reference half-cell contains a porous ceramic type of liquid junction are likely to produce misleading pH measurements under normal service conditions. The error arises from substantial liquid-junction potentials, associated with the porous ceramic plug, which vary with the ionic composition of the solution under test. The error is not revealed by conventional two-point calibration procedures, since the majority of standard buffer solutions have a similar total ionic strength, but will nevertheless be present when the unknown solution differs in ionic strength from the standardizing buffers. The size of the error is proportional to the ratio between the salt concentration in the standard buffers and the concentration present in the unknown solution, and varies from one electrode specimen to another. The fault was present in 24 out of 30 electrodes in normal use selected at random from seven laboratories, and the mean error was 0.2pH unit per 10-fold salt-concentration difference between standard and test solutions. It is estimated that errors of this order must be widespread in the recent literature. Older pH determinations are likely to be more reliable, since the original reference electrode design with a free-flowing liquid junction is apparently free from the artefact.     

Post-partum transient thyrotoxicosis: report of two cases

Two patients with post-partum transient thyrotoxicosis associated with painless thyroiditis and low radioactive iodine uptake were described. The surreptitious use of thyroid hormones or iodine was excluded. Although the clinical course was compatible with that of subacute thyroiditis, passing through the hyperthyroid, euthyroid, hypothyroid and recovery phase, the patients showed a sustained elevation of serum anti-thyroglobulin antibody titer during the entire phase of the disease. Moreover, the histological findings obtained by the thyroid biopsy performed in a case were characteristic of chronic lymphocytic thyroiditis. Furthermore, it was of interest that the disease recurred following every delivery in 2 cases, suggesting the possible role of immunological changes induced by pregnancy and delivery in the etiology of this disease.     

Weeds as a predominant food source: a review of the diet of common hamsters Cricetus cricetus in farmlands and urban habitats

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Lipids in the heart: a source of fuel and a source of toxins

PURPOSE OF REVIEW: How do lipids arrive in the heart and other tissues? This review focuses on new information on pathways of lipid uptake into the heart. RECENT FINDINGS: Fatty acids, the major cardiac fuel, are obtained from either lipoproteins or free fatty acids associated with albumin. The heart is the tissue with the most robust expression of lipoprotein lipase, and recent data attest to the importance of this enzyme in supplying optimal amounts of fatty acids for the heart. Genetic deletion of CD36 also shows that this transporter is important for cardiac uptake of lipids. Retinoid acquisition by the heart involves pathways parallel to those used for fatty acid uptake: a pathway for acquisition of core lipoprotein retinyl ester and another for nonlipoprotein retinol. Dilated lipotoxic cardiomyopathy is the consequence of excess lipid uptake. SUMMARY: Genetic modifications that affect lipid uptake, oxidation, and storage are being exploited to elucidate the pathophysiology of cardiomyopathies and to discover how lipids relate to heart failure in humans with obesity and diabetes mellitus. This information is likely to lead to new diagnostic categories of cardiomyopathy and more pathophysiologically appropriate treatments.     

Reputation as a common source of cooperation and violent conflict: The case of the noble feud in early modern Germany

Feuding was a near-universal phenomenon, and a classic topic of anthropology and sociology. This article focuses on feuding among nobles in early modern Germany. The German noble feud assumed characteristics that differentiated it from vendetta. It developed into a distinct institution in terms of its legal status, methods and social conditions. It presents a puzzle: most feuds punctuated ongoing relationships between people who were closely related and socially and economically interdependent. Nobles tended to feud against the very people from whose goodwill they had much to gain and from whose enmity much to lose. Examining it from an evolutionary perspective suggests an answer to a problem that traditional historical approaches have not convincingly explained. The article argues that the same dense web of ties that facilitated cooperation between nobles generated violent conflicts between them. Reputation played a crucial role in this environment. Feuds are best seen as mechanisms of costly signaling one's underlying qualities and commitment to aristocratic values.     

Transient thyrotoxicosis associated with infarction of a large thyroid adenoma

We report a 46-year-old male patient with a transient thyrotoxicosis that seems to have been caused by hemorrhagic infarction of a cold thyroid nodule. The serum level of triiodothyronine was markedly but transiently elevated, while the serum thyroxine level remained within the normal range. The resected nodule, measuring 8 x 7 x 5 cm, showed extensive degeneration and necrosis with viable follicles left only at the margin of the nodule. A transient thyrotoxicosis due to acute hemorrhagic infarction of autonomously functioning thyroid nodules has already been reported. This case showed that the phenomenon could occur even in cold thyroid nodules. Its implications were discussed in relation to the high incidence of impaired TSH response to TRH in patients with nodular goiter.     

Destructive thyrotoxicosis in a patient with anaplastic thyroid cancer

A 55-year-old man was admitted to our hospital with an anterior neck tumor, hoarseness, and dysphagia that had continued for a few weeks. He was diagnosed as anaplastic thyroid cancer by fine-needle aspiration cytology. He was treated by external radiation and chemotherapy, but left hemothorax developed and he died of respiratory failure on the 76th day in hospital. On admission, the levels of serum free triiodothyronine (FT3), free thyroxine (FT4), and TSH were 12.8 pg/ml, 4.2 ng/dl, and 0 microU/ml, respectively. The simultaneous thyroidal I-131 uptake rate was 1.2% at 24 hours. The levels of free thyroid hormones fell gradually without antithyroid drugs to result in hypothyroidism (FT3 0.8 pg/ml, FT4 0 ng/dl, and TSH 36 microU/ml). The rapid growth of anaplastic thyroid cancer seemed to be responsible for destructive thyrotoxicosis followed by hypothyroidism in this patient.     

Surgical treatment of thyrotoxicosis.

A retrospective study of thyrotoxic patients treated by subtotal thyroidectomy between 2 and 21 years ago in the north-east of Scotland showed that 20% of the patients could not be identified or traced at the time of the survey. The thyroid status of 40% of patients followed up was abnormal.It is now accepted that radioiodine treatment of thyrotoxicosis is followed by a significant incidence of late onset hypothyroidism, and life-long follow-up is regarded as obligatory. The findings in this study indicate that similar methods of aftercare are required for surgically treated patients and for all patients receiving thyroxine-replacement therapy.