Studies of biological factors associated with the inheritance of schizophrenia: A selective review

Although a familial component to schizophrenia has been established through several familial, twin and adoption studies, an inherited biological factor has yet to be established. Efforts to define clinical familial subtypes of schizophrenia have generally been unsuccessful, although recent data from our study population of pairs of siblings with schizophrenia suggests that schizophrenia with recurrent episodes of major depression may define one such group.

There have only been a few biological traits consistently found to be associated with schizophrenia and also found to be heritable. These findings (e.g. measures of monomine metabolism, brain structural morphology, neurophysiological markers, and protein polymorphisms) are reviewed in the present chapter. The proportion of patients with any of the noted abnormalities never approaches 100%, nor have any been found to be specific to schizophrenia. Research into the biogenetics of schizophrenia is clearly just beginning.     

Biochemical study and in vitro insect immune suppression by a trypsin‐like secreted protease from the nematode Steinernema carpocapsae

A trypsin‐like serine protease was purified by gel filtration and anion‐exchange chromatography from the excretory‐secretory products of parasitic phase Steinernema carpocapsae. The purified protease exhibited a molecular mass of about 29 kDa by SDS–PAGE and displayed a pI of 6·3. This protease exhibited high activity with trypsin‐specific substrate N‐Ben‐Phe‐Val‐Arg‐p‐nitroanilide and was highly sensitive to aprotinin and benzamidine. The purified trypsin protease digested the chromogenic substrate N‐Ben‐Phe‐Val‐Arg‐p‐nitroanilide with K_m, V_max and k_cat values of 594·2 μm , 0·496 μm /min and 22·8/s, respectively. The optimal pH and temperature for protease activity were 9 and 30°C, respectively. Internal amino acid sequencing yielded 150 amino acids and these were homologous to other trypsin sequences. In vitro investigation was carried out to monitor prophenoloxidase suppression in Galleria mellonella by the purified protease; about 38·9–52·6% suppression of prophenoloxidase was observed. The purified protease affected insect haemocyte spreading, causing cells to become spherical or round. Protease‐treated actin filaments were highly disorganized in haemocytes. In vitro, G. mellonella haemocytes recognized infective juveniles of Heterorhabditis bacteriophora; however, S. carpocapsae and Steinernema glaseri were not recognized. We provide experimental evidence that the purified trypsin has the potential to alter host haemocytes, actin filaments and to inhibit host haemolymph melanization.     

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.     

Detection of antisperm antibodies: a cytotoxicity immobilization test

The sera of 110 couples with unexplained infertility were examined for anti-sperm immobilizing antibodies with the aid of multiple-exposure photography. The sera of 10 females and 3 males had immobilizing activity. Eleven pregnancies occurred in 10 female patients in the group without immobilizing antibodies. None of the 13 females in the couples with immobilizing activity conceived. A negative correlation was found between the occurrence of serum immobilizing antibodies and incidence of pregnancy. No such correlation could be found between the occurrence of autoagglutination in the male's ejaculate and the female partner conceiving. In light of detection of anti-sperm antibodies in a patient with habitual abortions, a possible immune mechanism is suggested.     

Association of rapid mood switching with panic disorder and familial panic risk in familial bipolar disorder

OBJECTIVE: Comorbid bipolar and panic disorders aggregate in families. A phenotypic trait shared by both disorders is the sudden shift in affect observed in panic attacks and some rapid cycling states. The authors investigated whether comorbidity of bipolar disorder and panic disorder is associated with rapid mood switching in families with a high rate of bipolar disorder. METHOD: Six hundred six subjects with bipolar disorder from the NIMH Bipolar Disorder Genetics Initiative were included in the study. Logistic regression analysis was used to analyze rapid mood switching as a function of panic disorder diagnosis, sex, and familial risk for panic. RESULTS: Familial panic and the diagnosis of panic disorder in an individual subject increased the odds for rapid mood switching. The familial effect persisted when individuals with panic disorder were excluded from the analysis. CONCLUSIONS: Panic and rapid mood switching occurring together in familial bipolar disorder may define a useful subphenotype for future studies.     

Serotonin and its implication for the management of irritable bowel syndrome

Our understanding of the enteric nervous system (ENS) has evolved from the "classical" view, in which the brain controls all enteric behavior, to the current view, which holds that enteric innervation is one of local control within the bowel, modified by a bidirectional "dialogue" with the brain. The ENS independently controls enteric reflexes through intrinsic primary afferent neurons, which monitor intraluminal conditions. This monitoring is accomplished through the use of enteroendocrine cells in the mucosa, the best known of which are the serotonin-containing enterochromaffin cells. This article describes the roles that serotonin, specific serotonin-receptor subtypes, and the serotonin reuptake transporter play in the ENS and in the communication between the ENS and central nervous system. The way in which these findings have implicated serotonin in irritable bowel syndrome is discussed.     

Pilot Survey of Subway and Bus Stop Noise Levels

Excessive noise exposure is a serious global urban health problem, adversely affecting millions of people. One often cited source of urban noise is mass transit, particularly subway systems. As a first step in determining risk within this context, we recently conducted an environmental survey of noise levels of the New York City transit system. Over 90 noise measurements were made using a sound level meter. Average and maximum noise levels were measured on subway platforms, and maximum levels were measured inside subway cars and at several bus stops for comparison purposes. The average noise level measured on the subway platforms was 86 ± 4 dBA (decibel-A weighting). Maximum levels of 106, 112, and 89 dBA were measured on subway platforms, inside subway cars, and at bus stops, respectively. These results indicate that noise levels in subway and bus stop environments have the potential to exceed recommended exposure guidelines from the World Health Organization (WHO) and U.S. Environmental Protection Agency (EPA), given sufficient exposure duration. Risk reduction strategies following the standard hierarchy of control measures should be applied, where feasible, to reduce subway noise exposure.Gershon and Barrera are with the Department of Sociomedical Sciences, Columbia University, Mailman School of Public Health, 600 West 168th Street, 4th Floor, New York, NY 10032, USA; Neitzel is with the Department of Environmental and Occupational Health Sciences, University of Washington, Seattle, WA 98105, USA; Akram is with the Department of Environmental Health Sciences, Columbia University, Mailman School of Public Health, New York, NY 10032, USA.     

One-year audit of admissions to the Intensive Care Unit of the Queen Elizabeth Central Hospital,Blantyre

The intensive care unit at Queen Elizabeth Central Hospital (QECH) has 4 beds and offers level 2 care. A retrospective audit of all admissions to the unit during 2002 was carried out. There were a total of 339 admissions giving a bed occupancy rate of 82 %. Surgical patients made up 81 % of admissions. 45% of all admissions were ventilated. Overall mortality was 38%. Ventilated patients had a mortality of 71% compared with 10% for non-ventilated. Data are also presented for mortality within the surgical and paediatric surgical admissions.