Siriraj Medical Journal

189-193

Authors: Nitipatana Chierakul, M.D., Kanokwan Boonyapisit, M.D., Nukool Keurueangkul, M.D.

Objective: Sleep loss affects function of humans in terms of cognition, learning, and also memory. Suboptimum sleep is inevitable during residency training especially in internal medicine. Regulation of maximum hours of work per week and duty period for in-training physicians has been established in some countries, but not yet in Thailand. This study aims to describe the sleep hygiene, perception of reduced sleep hours, and daytime perfor- mance of internal medicine residents during the rst year of training in one major teaching hospital in Thailand. Methods: Self-administered questionnaires were distributed to rst-year internal medicine residents after informed consent at the time of orientation before training for baseline data, then at 6 and 12 months after training. Results: Among 56 participants, the mean age was 27 ± 1 years, and 30 of them were female. Average sleep hours was signi cantly decreased (p < 0.001) from 7.0 hr at baseline (M0) to 6.0 hr at month 6 (M6) and 6.1 hr at month 12 (M12). On the contrary, the Epworth Sleepiness Scale (ESS) was signi cantly increased after being the trainee (5.7/24 at M0, 8.6 at M6, and 8.0 at M12, p < 0.001). Perception of reduced sleep hours did not change signi cantly after training (42.9/65 at M0, 43.5 at M6, and 43.0 at M12, p > 0.46). Daytime function in terms of fatigue, irritability, depressed mood, impaired memory, poor concentration, and decreased learning ability were signi cantly increased at M6 and remained stable at M12, except for the further increment of irritability and impaired memory (p < 0.05). Con ict events with colleagues were signi cantly increased at M12 and medical errors were signi cantly increased at M6 and stable at M12 (p < 0.05). Conclusion: Internal medicine residency training greatly in uences the sleep quality of physicians. Tendency towards sleep loss may be one of the stressful environments determining their self-reported impairment of day- time functions.

210-218

Authors: Kittikun Viwatpinyo, M.D., D. Troy Case, Pasuk Mahakkanukrauh, M.D.

Foot bones are of interest for forensic sexing because of high reported accuracy in recent studies and often good preservation. This study investigated 202 pairs of navicular bones (104 males, 98 females) obtained from the Chiang Mai University Skeletal Collection. Metric measurements of eight dimensions of the navicular bone were taken with a digital caliper and analysed statistically to determine mean differences between the sexes and to calculate discriminant functions. Discriminant functions obtained from a combination of all variables had a pooled accuracy of 91.1% for the left navicular and 92.1% for the right. Using a stepwise method, discriminant functions showed 89.6% and 92.1% accuracy for left and right bones, respectively. In addition, the functions from stepwise method from either left or right side can be applied to the opposite side with similar obtained accuracy. Variables from the articular facets of the navicular bone had a high effect size and were included in all of our derived discriminant functions. We suggest that detailed measurement of articular facets could be useful for skeletal sexing.

225-230

Authors: Bijaylakshmi Parija, M.D., Niranjan Sahu, M.D., Shakti Rath, M.Sc., Rabindra N. Padhy, Ph.D.

ackground: Normal ageing and dementia cause the increase of ventricular size in brain, and it is necessary to ascertain ageing related changes in ventricle size in normal Indo-Dravidian people of southern Odisha, India. Objective: To nd out age-related changes in ventricular system of brain in normal individuals from younger to elderly groups in both sexes. Methods: Sixty normal females and males within ages, 15 to 70 years were examined by computed tomography (CT) scan of brains. Measurements of lateral, third and fourth ventricles were considered by arranging the subjects into 3 age-groups, 15 to 30, 31 to 50 and 51 to 70 years. After taking due measurements, Schaltenbrand index was calculated. Results: Size of all ventricles had insigni cant increase or no change from the youngest (15 to 30 years) to the middle age-group (31 to 50 years), but the width of third ventricle was found to increase in most males and females in the elderly group. Males had higher values of enlargement than females in all ventricles. Measurements of AP length of frontal horn and frontal horn with body remained almost constant in the youngest age-group, which increased with ageing. Schaltenbrand index values decreased steadily from younger to higher age-groups. Conclusion: Sizes of all three ventricles were more in elderly individuals. In both higher age-groups, males had more expansion of ventricular system than females. Increase in ventricular size was more evident in the lateral ventricle. Changes in ventricular size did not show any effective change in cranial diameters.

234-239

Authors: Chongdee Dangrat, B.Sc. (Biology), M.Sc. (Biochemistry)

Hyperprolactinemia is a common endocrine disorder which clinically manifestats in reproductive period and presents with hypogonadism, galactorrhea and symptoms related to tumor mass effects. Hyperprolactinemia is a state of excess total prolactin (PRL) concentration in serum. Three forms of PRL in sera are monomeric PRL with 23 kilo-dalton (kDa) MW which acts bioactively which is predominant in patients with prolactinomas, dimeric PRL; 45-60 kDa MW which is not clearly bioactive and macroprolactin with MW bigger than 100 kDa which is not bioactive. Macroprolactinemia is common and is associated with idiopathic hyperprolactinemia. Serum PRL is routinely screened for diagnosis of hyperprolactinemia. Nowadays, laboratory automatic analysis to measure serum PRL level using sandwich immunomatric methodology is accurate and reliable. Limitations of these immunoassays are interference from prolactin/IgG auto-antibody complex termed macroprolactin. This condition may lead to misdiagnosis and mismanagement of cases because the total PRL measurement comprises macroprolactin and active PRL. Using 25% polyethylene glycol (PEG) precipitation quantitatively provides the bioactive PRL by gel ltration chromatography which remains the gold standard to fractionate the level of PRL concentration. Recommended cut point recoveries of PRL less than 40% or 50% is indicative of the predominance of macroprolactin whereas more than 50% or 60% is diagnosed as true hyperprolactinemia. PEG precipitation is the best practice and recommended as the worldwide method to divide macroprolactin and active PRL for detection of the true origin because it is reproducible, easily performed and is effective screening. This review emphasizes about pathophysiology of hormone PRL and expresses the necessary method to clarify between macroprolactinemia and truly hyperprolactinemia.