The calpain system

The calpain system originally comprised three molecules: two Ca2+-dependent proteases, mu-calpain and m-calpain, and a third polypeptide, calpastatin, whose only known function is to inhibit the two calpains. Both mu- and m-calpain are heterodimers containing an identical 28-kDa subunit and an 80-kDa subunit that shares 55-65% sequence homology between the two proteases. The crystallographic structure of m-calpain reveals six "domains" in the 80-kDa subunit: 1). a 19-amino acid NH2-terminal sequence; 2). and 3). two domains that constitute the active site, IIa and IIb; 4). domain III; 5). an 18-amino acid extended sequence linking domain III to domain IV; and 6). domain IV, which resembles the penta EF-hand family of polypeptides. The single calpastatin gene can produce eight or more calpastatin polypeptides ranging from 17 to 85 kDa by use of different promoters and alternative splicing events. The physiological significance of these different calpastatins is unclear, although all bind to three different places on the calpain molecule; binding to at least two of the sites is Ca2+ dependent. Since 1989, cDNA cloning has identified 12 additional mRNAs in mammals that encode polypeptides homologous to domains IIa and IIb of the 80-kDa subunit of mu- and m-calpain, and calpain-like mRNAs have been identified in other organisms. The molecules encoded by these mRNAs have not been isolated, so little is known about their properties. How calpain activity is regulated in cells is still unclear, but the calpains ostensibly participate in a variety of cellular processes including remodeling of cytoskeletal/membrane attachments, different signal transduction pathways, and apoptosis. Deregulated calpain activity following loss of Ca2+ homeostasis results in tissue damage in response to events such as myocardial infarcts, stroke, and brain trauma.     

Salivary immunoglobulins in a patient with IgA deficiency

The saliva of an individual with selective IgA deficiency was found to contain IgG and IgM, with some of the IgM linked to secretory component. Some specimens showed evidence of low molecular weight immunoglobulin fragments, presumed to be the result of proteolysis.     

Risk and protective factors for suicidal behavior in abused African American women

This study examined risk and protective factors that differentiate low-income, abused African American women (N = 200) who attempted suicide from those who had never made a suicide attempt. Results from multivariate analyses revealed that numerous and/or severe negative life events, a history of child maltreatment, high levels of psychological distress and depression, hopelessness about the future, and alcohol and drug problems were factors associated with attempter status. Protective factors associated with nonattempter status included hopefulness, self-efficacy, coping skills, social support, and effectiveness in obtaining material resources. Culturally competent intervention approaches for abused women should target increasing their protective factors and reducing their risk factors to decrease the likelihood that these women engage in suicidal behavior.     

Changes in human muscle transverse relaxation following short-term creatine supplementation

The rapid increase in body mass that often occurs following creatine (Cr) supplementation is believed to be due to intracellular water retention. The purpose of this study was to determine whether Cr consumption alters the magnetic resonance (MR) transverse relaxation (T(2)) distribution of skeletal muscle. Transverse relaxation can be used to model water compartments within a cell or tissue. In this double-blind study, subjects were asked to supplement their normal diet with creatine monohydrate (20 g day(-1) for 5 days) mixed with a grape drink (Creatine group, n = 7), or the grape drink alone (Placebo group, n = 8). Phosphorous MR spectroscopy was used to determine the effectiveness of the supplementation protocol. Subjects that responded to the Cr supplementation (i.e. showed a > 5 % increase in the ratio of the levels of phosphocreatine (PCr) and ATP) were placed in the Creatine group. Both proton MR imaging and spectroscopy were used to acquire T(2) data, at 1.89 T, from the flexor digitorum profundus muscle of each subject before and after supplementation. Following the supplementation period, the Creatine group showed a gain in body mass (1.2 +/- 0.8 kg, P < 0.05, mean +/- S.D.), and an increase in PCr/ATP ratio (23.8 +/- 16.4 %, P < 0.001). Neither group showed any changes in intracellular pH or T(2) calculated from MR images. However, the spectroscopy data revealed at least three components (> 5 ms) at approximately 20, 40 and 125 ms in both groups. Only in the Creatine group was there an increase in the apparent proton concentration of the two shorter components combined (+5.0 +/- 4.7 %, P < 0.05). According to the cellular water compartment model, the changes observed in the shorter T(2) components are consistent with an increase in intracellular water.     

Use of tri-gas incubator for routine culture of Campylobacter species from fecal specimens.

We evaluated a tri-gas incubator for Campylobacter isolation to be used instead of an anaerobic jar. Fecal specimens were cultured in duplicate onto charcoal selective medium and incubated at 43 degrees C for 48 h in two different environments: a tri-gas incubator (Forma Scientific) adjusted to provide an atmosphere of 10% CO2, 10% O2, and the balance N2; and evacuated anaerobic jars with a replacement gas mixture of 10% CO2, 5% O2, and 85% N2. A total of 106 Campylobacter jejuni and 8 Campylobacter coli isolates were obtained from 2,348 stool specimens. Of the positive specimens, 113 isolates came from the incubator and 111 isolates came from the anaerobic jars. An additional 32 previously positive specimens were replated onto charcoal selective medium and retested by both methods. We recovered 27 C. jejuni isolates, 26 isolates by each method. The isolates from the incubator typically produced discrete colonies, while the isolates from the anaerobic jar showed some degree of swarming in colony formation. The tri-gas incubator provided a cost-effective method for culturing Campylobacter spp.     

Cooperation between surgical oncologists and pathologists: a key element of multidisciplinary care for patients with cancer

For patients with cancer it is essential to reach a definite diagnosis, obtain accurate staging and provide appropriate initial treatment if a successful outcome is to be achieved. These fundamental first steps in multidisciplinary care require close cooperation between surgical oncologists and pathologists. The most important aspect of this cooperation is clear and free exchange of information between them. The surgeon should provide the pathologist not only with an adequate tissue sample for examination, but also with clinical details that will assist in establishing a diagnosis. The location and orientation of specimens, and areas of particular concern, should always be indicated. Operative digital photographs may assist this process. The pathologist, in return, should provide the surgeon with a report containing sufficient information to allow an evidence-based management plan to be made for the patient, and to permit an accurate indication of prognosis to be determined. Use of a disease-specific synoptic report format will ensure that potentially important information is not overlooked. When there is diagnostic uncertainty, the pathologist should make this clear, but provide a preferred diagnosis. Further opinions may be helpful. If doubt exists, medico-legal considerations should not encourage a pathologist to issue a report with a diagnosis of malignancy. The pathologist should refrain from making management recommendations, because there may be valid reasons for the surgeon not providing this management. By cooperating fully and communicating freely with each other, surgical oncologists and pathologists can ensure high standards of initial and subsequent care for cancer patients.     

Effects of immunization and anticoagulation on the development of experimental Escherichia coli endocarditis.

The effects of immunization and anticoagulation in experimental Escherichia coli endocarditis were studied. Immunization of rabbits with E. coli resulted in the development of specific agglutinating and opsonic activity of the serum, but not in bactericidal activity. These antibody activities also developed in nonimmunized rabbits during the course of bactericidal endocarditis. Immune serum promoted phagocytosis in vitro but did not enhance intracellular killing of E. coli by elicited rabbit peritoneal macrophages. The presence of specific antibodies in rabbits after immunization had no effect on the induction or course of E. coli infection of endocardial vegetations. Anticoagulation was found to affect the induction of the infection. In anticoagulated rabbits, larger bacterial inocula were needed to induce an infection, but in animals with bacterial endocarditis the number of bacteria in the vegetations did not differ significantly from that of the control animals.     

Circulating immune complexes in patients with cryptogenic fibrosing alveolitis.

Increased Clq binding levels have been obtained in serum from twenty-one (50%) of forty-two patients with cryptogenic fibrosing alveolitis (CFA) suggesting the presence of circulating immune complexes. There was a low frequency of positive results using a number of other tests for circulating immune complexes. The increased Clq binding levels were observed in six (35%) out of seventeen patients with lone lung involvement and in fifteen (60%) out of twenty-five patients with extrapulmonary connective tissue disorders. There was an especially close correlation between arthritis and elevated Clq binding. A strong correlation between Clq binding levels and levels of circulating rheumatoid factor (RF) and IgG, and enhancement in macrophage radiobioassay tests using RF-containing sera, suggested that RF might be involved in the circulating immune complexes in these patients. DNAase pre-treatment of sera did not influence the findings, and there was no correlation between Clq binding and levels of immunofluorescent ANA, C-reactive protein levels, or platelet counts. A weak correlation between Clq binding and erythrocyte sedimentation rates, and slightly lower binding levels in treated than untreated patients with 'lone' CFA suggested that binding levels may give some indication of disease activity and may in some instances be influenced by treatment.     

Evaluation of an educational programme to improve the recognition of psychological illness by general practitioners.

BACKGROUND: Take Care is a commercially sponsored educational package for the detection and management of depression by all members of the primary health-care team. AIM: This study was designed to evaluate whether the educational package affects the recognition of psychological illness by general practitioners. METHOD: General practitioners working in 13 practices in North West England or Trent Regional Health Authorities took part the evaluation. Patients who scored more than eight on the depression or anxiety component of the Hospital Anxiety and Depression (HAD) scales, and who were thought by their general practitioner to have a totally physical problem or no illness, were deemed to have a psychological illness that had been 'missed' by the doctor. Changes in the proportion of missed cases before and after exposure to Take Care were estimated. RESULTS: When all practices were considered together, the general practitioners missed a depressive illness in 24.1% of patients before Take Care, and 17.1% afterwards; absolute decrease 7.0% [95% confidence interval (CI) -2.0 to -12.0%]. An improvement was seen in most practices (Wilcoxon matched-pair test P < 0.05). The programme was also associated with a small reduction in the overall proportion of episodes of anxiety missed by the doctor (absolute decrease 4.5%; 95% CI -1.0 to -8.0%) a reduction was found in most practices (Wilcoxon matched-pair test P < 0.05). There was no material difference in the diagnostic false-positive rate of the doctors before and after the introduction of the programme. CONCLUSION: Exposure to an educational package for depression was associated with improved recognition of psychological illness by general practitioners.