Concanavalin A induced apoptosis in murine macrophage PU5-1.8 cells through clustering of mitochondria and release of cytochrome c

Concanavalin A (ConA), normally a mitogen of T-lymphocytes, was found to be a cell cycle-independent apoptosis-inducing agent in cultured murine macrophage PU5-1.8 cells. This assertion is based on the following observations: (1) ConA increased the number of cells with hypodiploid DNA in a dose dependent manner as revealed by flow cytometry; (2) ConA elicited DNA fragmentation and the cytotoxicity of ConA was suppressed by alpha-D-methylmannoside which blocks the lectin site of ConA; (3) ConA was able to release cytochrome c (cyto c) into the cytosol of PU5-1.8 cells. When isolated mitochondria were incubated with ConA, release of cyto c was observed too. Interestingly, clustering of mitochondria was found in the cytosol under a confocal microscope after ConA treatment. When cells were incubated with ConA-FITC and subsequently with mitotracker red (a probe for mitochondria), co-localization of fluorescence signals was observed. These results suggest that ConA was delivered to the mitochondria, induced mitochondrial clustering and released cyto c. Our results also show that introduction of exogenous cyto c electroporationally into ConA-untreated cells elicited DNA fragmentation. On the other hand, introduction of specific antibody against cyto c into PU5-1.8 cells suppressed the ConA-mediated cell death. Taken together, our results indicate that ConA induced apoptosis in PU5-1.8 cells through mitochondrial clustering and release of cyto c and the release of cyto c was sufficient to elicit apoptosis in PU5-1.8 cells.

Painful leg and missing pulses: a case report

Popliteal artery entrapment syndrome (PAES) is a rare but potentially limb threatening anatomical anomaly occurring predominantly in young adults. We report a case of a 14 year old boy who presented with limb threatening ischaemia requiring urgent surgery. The pathology, presentation, and management are discussed.

Quality of life in Chinese women with gynaecological cancers

Sixty-two Hong Kong Chinese women with gynaecological cancers participated in this cross-sectional study to assess their quality of life (QOL). Chinese versions of the World Health Organisation Quality of Life Measure--abbreviated version, the Profile of Mood States, and the Sexual Relationships subscale of the Psychosocial Adjustment to Illness Scale were used. Qualitative data were collected about the meaning of QOL and the areas of life most affected by the cancer and its treatments. The overall QOL was found to be moderate (mean 92.4, SD 16.34), with the domains of psychological health and social relationships most affected. The distressed facets of life were related to pain, dependency, finances, sexuality, psychological health and spirituality. Mobility, accepting one's outlook, social support and "eating" were areas considered by these women to contribute to a better QOL. The meaning of QOL was described in terms of happiness and material resources. The overall mood score was found to be impaired (mean 43.84, SD 32.31), with relatively high scores for depression, anger and tension. Depression could explain 45% of the variance in the QOL. Despite some missing data, sexual relationships among the respondents were moderately affected, with reduced sexual desire and activity. However, the patients' relationships with their husbands were minimally affected, suggesting the men's understanding and support in the cancer trajectory of their wives. Areas of life that may need further support, such as sexual functioning and psychosocial adjustment, could be improved by the use of sex therapy or group support interventions. Limitations of the present study and suggestions for future research are discussed.

Mechanical characterization of regenerated osseous tissue during callotasis and its related biological phenomenon

The mechanical characteristics of the regenerated osseous tissue and osteoblastic activities during callotasis were studied using Chinese mountain goat as the animal model. Open osteotomy of the left tibiae was done in 24 goats. Distraction started 6 days after the operation with the rate of 1 mm per day for 4 weeks. The bone regeneration was monitored with serial X-ray films. The tension generated during distraction was measured with the strain gauges mounted on the distraction apparatus. The osteoblastic activities were monitored by measuring plasma bone specific alkaline phosphatase activity. The results showed that the average lengthening was 22.9 +/- 2.8 mm in each animal. The newly formed osseous tissue becomes stiffer during the course of distraction lengthening. The continuous evolution of the tensile behaviour of the newly formed osseous tissue correlates with the plasma bone specific alkaline phosphatase activities. The radiological appearance of a physis like structure took place at 12 mm lengthening. Its appearance corresponds to the changes in the tensile behaviour as well as the biological activities of the osteoblasts and may serve as a useful radiological marker in monitoring the process of callotasis in clinical practice.

The transmission of Lamb waves across adhesively bonded lap joints

The transmission of Lamb waves across adhesively bonded lap joints is investigated using finite element analysis. The studies consider three modes for excitation and reception, s0, a0, and a1, applied to lap joints consisting of parallel aluminum sheets bonded with an epoxy adhesive. Transmission coefficient results for a two-dimensional range of bond thicknesses and bond overlap lengths are presented for all three modes. The transmission coefficients are calculated from the spectra of the received and transmitted signals using an approach which is insensitive to the presence of multimode signals and reverberated signals, and which approximates to a power transmission coefficient. Detailed analysis is then performed for one of the modes in order to investigate the nature of the mode conversion in the overlap region of the joint. It is found that the relative amplitudes of the different modes which propagate in the overlap region can be estimated reliably and simply from the properties of the incident wave mode. As well as demonstrating the physics of the mode conversion behavior, the study provides a basis for the selection of modes for nondestructive evaluation (NDE) of the bond region and for measuring the bond dimensions.

Risk factors for anastomotic leakage after low anterior resection with total mesorectal excision

BACKGROUND

This study aims to analyze the risk factors for anastomotic leakage after low anterior resection with the technique of total mesorectal excision (TME).

METHODS

From September 1993 to November 1998, 196 patients with rectal cancer from 3 to 12 cm from the anal verge were treated with low anterior resection with TME. The data were entered in a prospective manner, and the factors that might affect anastomotic leakage were analyzed.

RESULTS

The mean level of anastomosis was 3.6 cm from the anal verge (range 1 to 5 cm). The leakage rate was 10.2%. Female gender (P = 0.01; 95% confidence interval [CI] 1.3 to 14.3; odds ratio 4.3) and presence of a diversion stoma (P = 0.01; 95% CI 1.4 to 14.2; odds ratio 4.5) were independent significant factors for lower anastomotic leakage. The absence of a stoma was associated with significantly increased leakage in male (P = 0.001) but not in female (P = 0.51) patients.

CONCLUSIONS

With low anastomosis after low anterior resection with TME, diversion stoma construction should be performed routinely in men. In women, the need for diversion can be more selective.

Results of revision total knee arthroplasty

BACKGROUND/AIM OF STUDY

The results of primary total knee arthroplasties have improved over the years but some still fail, requiring revision. Revision total knee arthroplasty is technically more difficult and has not enjoyed the same success rates as the index operation. The aim of this retrospective study was to review the results of revision total knee arthroplasties carried out at our centre. This is the first study in Singapore on revision total knee arthroplasty.

METHODS

A retrospective study where 17 patients (18 knees) had been followed up since their revision operations were clinically assessed. Based on the Knee Society Clinical Scoring System, they were assigned separate knee and function scores (each having a maximum possible 100).

RESULTS

The mean knee score was 76 (range 35-93), which rates as good. Of the 18 knees, 67% had excellent or good knee scores. By comparison, the mean function score was 56 (range 0-90) which rates as poor and 33% had excellent or good function scores.

CONCLUSION

Revision total knee arthroplasty achieves good and excellent results in spite of technical difficulties often associated with the revision operation. The difference in mean knee and function scores emphasises that many other factors such as physical strength and stamina affect function. Nevertheless, 15 patients were able to walk out of their house and around their neighbourhood for varying distances. This satisfied their expectations and the poor mean function score may reflect different expectations of patients overseas from whence this scoring system originated.

Computerized analysis of lesions in US images of the breast

RATIONALE AND OBJECTIVES

Breast sonography is not routinely used to distinguish benign from malignant solid masses because of considerable overlap in their sonographic appearances. The purpose of this study was to investigate the computerized analyses of breast lesions in ultrasonographic (US) images in order to ultimately aid in the task of discriminating between malignant and benign lesions.

MATERIALS AND METHODS

Features related to lesion margin, shape, homogeneity (texture), and posterior acoustic attenuation pattern in US images of the breast were extracted and calculated. The study database contained 184 digitized US images from 58 patients with 78 lesions. Benign lesions were confirmed at biopsy or cyst aspiration or with image interpretation alone; malignant lesions were confirmed at biopsy. Performance of the various individual features and output from linear discriminant analysis in distinguishing benign from malignant lesions was studied by using receiver operating characteristic (ROC) analysis.

RESULTS

At ROC analysis, the feature characterizing the margin yielded Az values (area under the ROC curve) of 0.85 and 0.75 in distinguishing between benign and malignant lesions for the entire database and for an "equivocal" database, respectively. The equivocal database contained lesions that had been proved to be benign or malignant at cyst aspiration or biopsy. Linear discriminant analysis round-robin runs yielded Az values of 0.94 and 0.87 in distinguishing benign from malignant lesions for the entire database and for the equivocal database, respectively.

CONCLUSION

Computerized analysis of US images has the potential to increase the specificity of breast sonography.

Partial patellectomy induces a decrease in the proteoglycan content in the remaining patellar articular cartilage. An experimental study in rabbits

We studied the alterations and distribution of the proteoglycan (PG) content of the remaining patellar articular cartilage after unilateral partial patellectomy in 13 rabbits. Sagittal sections of the patella were prepared and stained with Safranin O for quantification of changes in the PG content of the patellar articular cartilage using a commercially available imaging analysis system. Our findings suggest that partial patellectomy results in a decreased PG content in the remaining patellar articular cartilage. In addition, the postoperative development of metaplasia in the scar tissue next to the healing interface may represent a compensatory response, which could prevent a further reduction in the PG content and hence the development of osteoarthritis in the remaining patellar articular cartilage.

Stress associated with tasks for family caregivers of patients with cancer in Hong Kong

Family caregivers share the strain of cancer and are at risk of physical and psychological symptoms in relation to caregiver stress. This study investigated the relationships between perceived difficulty in managing caregiver tasks and the experience of stress symptoms among 26 family caregivers of terminally ill patients with cancer in Hong Kong. The findings revealed that more stress symptoms were experienced by caregivers who had reported increased difficulty in managing caregiver tasks (rs = 0.64; p < 0.001). Wilcoxon signed-ranks test indicated that psychological stress symptoms, rather than physical symptoms, overwhelmed most of the caregivers (z = -2.15; p < 0.05). There were significantly more negative responses to stress by caregivers who had a shorter duration of experience in providing care. In addition, caregivers who had less education were at higher risk of developing stress (p < 0.01). These findings indicate the need for the provision of support to facilitate the emotional and physical adaptation of caregivers at risk for health problems.

Prospective evaluation of selective defunctioning stoma for low anterior resection with total mesorectal excision

Low anterior resection with total mesorectal excision for rectal carcinoma is associated with a high anastomotic leakage rate, and the effectiveness of a defunctioning stoma in preventing anastomotic leakage remains controversial. In this study a policy of selective defunctioning stoma for stapled colorectal anastomosis after low anterior resection with total mesorectal excision in 148 consecutive patients was evaluated prospectively. A defunctioning stoma was performed in 61 patients (41%) considered at high risk of anastomotic leakage. Clinical leakage occurred in 2 patients (3.3%) with a stoma and 11 patients (12.6%) without a stoma (p = 0.047). Among those without a stoma, the leakage rate among male patients (20.9%) was significantly higher than that for female patients (4. 5%) (p = 0.022). Leakage subsided with conservative treatment in the two patients with a stoma, but seven patients without a stoma developed peritonitis requiring laparotomy. No deaths resulted from leakage, and there was one hospital death (0.6%) in the whole group. Median hospital stay was similar with and without a stoma (13.0 vs. 12.0 days) (p = 0.290). Closure of the stoma was associated with no mortality, a morbidity rate of 8.7%, and a median hospital stay of 6. 0 days. In conclusion, a defunctioning stoma is effective in preventing clinical anastomotic leakage after low anterior resection with total mesorectal excision. The relatively high incidence of leakage in the low risk group indicates the difficulty of predicting anastomotic leakage and hence the need for more liberal use of a defunctioning stoma especially in male patients.

A new multigene family encoding calcium-dependent calmodulin-binding membrane proteins of Paramecium tetraurelia

Ca2+/calmodulin (CaM) regulates various physiological processes in a wide variety of organisms, metazoa and protists alike. To better understand Ca2+/CaM-dependent processes, particularly those with membrane-associated components, we studied Ca2+/CaM-binding membrane proteins in Paramecium tetraurelia, a unicellular model system. A CaM-binding protein, PCM1 (Paramecium CaM-binding membrane-bound protein), from a detergent-solubilized ciliary membrane fraction was identified and purified through Ca2+-dependent CaM-affinity chromatography. PCM1 has an apparent molecular mass of approx. 65kDa. It binds radiolabeled CaM in blot overlay assays and binds to CaM-affinity columns, both only in the presence of 10 microM or higher Ca2+. Three peptide sequences from PCM1 were obtained, and polymerase chain reaction (PCR) and Southern hybridization experiments were designed accordingly, leading to a partial cDNA clone for PCM1 and the discovery of three homologs: PCM2, PCM3 and PCM4. Amino acid sequences predicted by the full-length coding sequence for PCM3 and partial genes for PCM1, PCM2 and PCM4 are very similar (approx. 85% amino-acid identities). Their sequences indicate that they are hitherto novel proteins with beta/gamma-crystallin domains, cysteine-rich regions and potential CaM-binding domains. These protein motifs are suggested to mediate protein-protein interaction important for Ca2+/CaM signal transduction event(s) through the PCM family of proteins.

Enlargement of remaining patella after partial patellectomy in rabbits

PURPOSE

The purpose was to study the radiographic patellar tendon calcification and evaluate the histology of the healing interface between the patellar tendon and the remaining patella after partial patellectomy.

METHODS

We removed the distal one-third of the patella in 24 rabbits. Specimens were harvested at 8, 12, and 24 wk postoperatively (N = 8 each).

RESULTS

Histological observation demonstrated that healing interfaces between the patellar tendon and patella were structurally connected by scar tissue. The radiographic patellar tendon calcification next to the healing interface was in fact trabecular bone outgrowth histologically, resulting in an enlargement of the remaining patellar in length from 0.93+/-0.28 mm at week 8, 1.26+/-0.33 mm at week 12, to 2.5+/-1.12 mm at week 24. Metaplasia of the scar tissue observed next to the healing interface of the remaining patellar articular cartilage and the outgrowth of trabecular bone from the remaining patella with healing over time may increase the articular surface of the remaining patella after partial patellectomy.

CONCLUSIONS

The remaining patella might be enlarged in length after partial patellectomy because of trabecular bone outgrowth and metaplasia with healing over time. Its theoretical advantages are an increased patellofemoral contact area and a diminished patellofemoral contact pressure following surgery.

Managing caregiver tasks among family caregivers of cancer patients in Hong Kong

Twenty-nine family caregivers of terminally ill cancer patients in Hong Kong were asked about their perceived difficulty in managing caregiver tasks. Results showed that the level of difficulty in handling the three main aspects of tasks, that is the direct care, intrapersonal tasks, and interpersonal ties, were similar (chi2 = 0.71, P > 0.05). The individual tasks identified as extremely difficult included compensation for personal time (31%), updating knowledge of reimbursement mechanism (20.7%), and emotionally accepting the likelihood of a progressive downward course of illness (17.2%). Mann-Whitney tests indicated that caregivers who had a shorter duration of caregiving experience perceived significantly greater difficulty in direct care (P < 0.05), intrapersonal tasks (P < 0.05), and overall tasks (P < 0.05). These findings indicate the need for the provision of counselling and educational support for these caregivers.

Studies of melatonin effects on epithelia using the human embryonic kidney-293 (HEK-293) cell line

The expression of melatonin receptors (MR) of the Mel1a subtype in basolateral membrane of guinea pig kidney proximal tubule suggests that melatonin plays a role in regulating epithelial functions. To investigate the cellular basis of melatonin action on epithelia, we sought to establish an appropriate in vitro culture model. Epithelial cell lines originating from kidneys of dog (MDCK), pig (LLC-PK1), opossum (OK), and human embryo (HEK-293) were each tested for the presence of MR using 2-[125I]iodomelatonin (125I-MEL) as a radioligand. The HEK-293 cell line exhibited the highest specific 125I-MEL binding. By intermediate filament characterization, the HEK-293 cells were determined to be of epithelial origin. Binding of 125I-MEL in HEK-293 cells demonstrated saturability, reversibility, and high specificity with an equilibrium dissociation constant (Kd) value of 23.8 +/- 0.5 pM and a maximum number of binding sites (Bmax) value of 1.17 +/- 0.11 fmol/mg protein (n = 5), which are comparable with the reported Kd and Bmax values in human kidney cortex. Coincubation with GTPgammaS (10 microM) and pertussis toxin (100 ng/ml) provoked a marked decrease in binding affinity (Kd was increased by a factor of 1.5-2.0), with no significant difference in Bmax. Melatonin (1 microM) decreased the forskolin (10 microM) stimulated cAMP level by 50%. HEK-293 cells do not express dopamine D1A receptor. Following transient transfection of HEK-293 cells with human dopamine D1A receptor (hD1A-R), exposure of the cells to dopamine stimulated an increase in the level of cAMP. Similarly, transient transfection of HEK-293 cells with rat glucagon-like peptide-1 (GLP-1), glucose-dependent insulinotropic peptide (GIP), and PTH type 1 receptors, each resulted in an hormone inducible increase in cAMP levels. Surprisingly, only the stimulatory effect of dopamine could be inhibited by exposure to melatonin. The inhibitory effect of melatonin on dopamine D1-induced increase in cAMP was completely inhibited by pertussis toxin (100 ng/ml, 18 h). Immunoblot and immunocytochemical studies were carried out using two polyclonal antibodies raised against the extra and cytoplasmic domains of Mel1a receptor. Immunoblot studies using antibody against the cytoplasmic domain of Mel1a receptor confirmed the presence of a peptide blockable 37 kDa band in HEK-293 cells. Indirect immunofluorescent studies with both antibodies revealed staining predominantly at the cell surface, but staining with the antibody directed against the cytoplasmic domain required prior cell permeabilization. By RT-PCR, HEK-293 cells express both Mel1a and Mel1b messenger RNAs, but the messenger RNA level for Mel1b is several orders of magnitude lower than for Mel1a. We conclude that HEK-293 cells express MR predominantly of the Mel1a subtype. Our evidence suggests that one of the ways that melatonin exerts its biological function is through modulation of cellular dopaminergic responses.

Bamboo skewer perforation of the bowel: computed tomography appearances

A 25-year-old Chinese woman presented with a painful left-lower-quadrant abdominal mass. Computed tomography (CT) demonstrated a dense forked foreign body within an extraluminal mass. A 2.5 cm bamboo skewer surrounded by inflamed omentum was found at laparotomy. Different CT densities of bamboo skewers were obtained when exposed to air, water and 2% Gastrografin in an in vitro experiment. Awareness of the possible variations in appearances of wooden foreign bodies in and around the bowel may aid their CT diagnoses.

Waddell's nonorganic signs and Minnesota Multiphasic Personality Inventory profiles in patients with chronic low back pain

STUDY DESIGN

An analysis of clinical data gathered at an orthopedic outpatient clinic is presented.

OBJECTIVE

To examine the relationship between Waddell scores and the Minnesota Multiphasic Personality Inventory response patterns.

SUMMARY OF BACKGROUND DATA

Waddell's study of nonorganic signs of low back pain showed consistent correlations with Minnesota Multiphasic Personality Inventory scales 1 to 3.

METHODS

A Waddell score was obtained from 507 consecutive patients with chronic low back pain to whom an Minnesota Multiphasic Personality Inventory also was administered. The sample was divided into those patients with a high Waddell score (high waddell score = 3 to 5) and those with a low Waddell score (low waddell score = 0 to 2); men and women were scored separately.

RESULTS

Among male patients, statistically significant differences were found between the high Waddell score and low Waddell score groups on Minnesota Multiphasic Personality Inventory scales, 1, 3, and 8, but among females, differences were statistically significant only on scale 8.

CONCLUSIONS

Correlations between the Waddell score and the first three scales of the Minnesota Multiphasic Personality Inventory were not fully replicated. The difference between the high Waddell and low Waddell groups on scale 8, however, was significant for men and women.

Studies of the renal action of melatonin: evidence that the effects are mediated by 37 kDa receptors of the Mel1a subtype localized primarily to the basolateral membrane of the proximal tubule

The pineal hormone melatonin controls circadian behavior of a variety of organs in different species, including humans. However, the precise mechanism (or mechanisms) by which this occurs remains largely unknown. At the cellular level its effects are believed to be mediated via interaction with specific melatonin receptors (MR), which have previously been cloned from human brain (Mel1a) and retina (Mel1b). At the tissue level, MR have been investigated primarily through empirical definition of specific binding sites, but so far there has been little success in biochemical or molecular characterization of native MR. In the kidney, there is strong circumstantial evidence that melatonin affects diurnal variations in renal function, but relatively little is known about the overall glomerular vs. tubular contributions to these effects. The strategy behind the present study was to use a panel of peptide-specific antibodies to identify MR proteins in various tissues, and from a determination of the intrarenal distribution of MR, gain insight into the mechanism by which melatonin might regulate kidney function. We used two peptide-specific antibodies directed against different regions of Mel1a to identify MR. Our results show that the native Mel1a receptor is a 37 kilodalton (kDa) protein in human and rat brain. Further, immunofluorescent studies carried out in guinea pig kidney have revealed that anti-Mel1a antibody is also localized to the basolateral membrane (BLM) of the renal cortical epithelium, especially the early proximal tubule. Immunoblotting of purified BLM fractions from guinea pig renal cortex and small intestine using the two different peptide-specific antibodies reveals the presence of a single peptide-blockable band at 37 kDa. These same BLM fractions also demonstrate the presence of high-affinity 2-[125I]iodomelatonin (125I-MEL) binding sites, with the pharmacological specificity of binding expected of the Mel1a receptor subtype, inhibited by guanosine 5'-O-(3'-thiotriphosphate) (GTPgammaS) and pertussis toxin. We conclude that functional MR in guinea pig kidney and small intestine are of the Mel1a subtype, and are expressed as 37 kDa proteins localized to the BLM and coupled to a pertussis toxin-sensitive G-protein (Gi). This localization strongly suggests that the proximal tubule plays a significant role in mediating the renal action of melatonin.

Concanavalin A-induced apoptosis in murine macrophages through a Ca(2+)- independent pathway

Concanavalin A (ConA), normally a mitogen of T lymphocytes, was found to induce apoptosis or programmed cell death in murine peritoneal macrophages. The following observations support this assertion: 1) incubation of peritoneal macrophages or cultured PU5-1.8 macrophage cells with ConA caused a dose- and time-dependent reduction of mitochondrial dehy-drogenase activity as measured by 3-(4,5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assay, 2) treatment of cells with ConA induced formation of apoptotic bodies as seen under the confocal laser scanning microscope, 3) challenge of cells with ConA produced a considerable amount of cell debris with DNA content next to G0 phase as revealed by flow cytometry and 4) ConA was able to elicit DNA fragmentation in these cells. The involvement of Ca(2+) in mediating the apoptosis was studied in single cells by confocal laser scanning microscope using the Ca(2+) fluorescence dye, fluo-3. Our results show that ConA induced an immediate rise of intracellular free Ca(2+) concentration as well as opening of Ca(2+) channels on cell surface. But when the cells were treated with 1,2-bis(o-aminophenoxy) ethane-N, N, N', N'-tetraacetic acid/AM (BAPTA/AM), a Ca(2+) chelator, to buffer the rise of internal Ca(2+), ConA still caused DNA fragmentation. Furthermore, injection of Ca(2+) into the cell with ionomycin had no stimulatory effect on DNA fragmentation. These results suggest that Ca(2+) changes induced by ConA are not a prerequisite for apoptosis in macrophages.

The absence of a B allele in acquired B blood group phenotype confirmed by a DNA based genotyping method

A case of an 87 year old woman with carcinomatous sigmoid colon, found to be of group A1 with acquired B status, is reported. The acquired B phenotype was confirmed by the absence of a B allele in the patient using denaturing gradient gel electrophoresis of a DNA fragment amplified from the ABO locus by the polymerase chain reaction.

Comparison of [125I]iodomelatonin binding sites in infant cerebellum of sudden infant death syndrome and non-sudden infant death syndrome

[125I]Iodomelatonin bindings sites in human infant cerebellum were studied by radioligand receptor binding assay and in vitro quantitative autoradiography. The binding sites characterized in membrane preparations revealed saturable, reversible and highly specific binding sites with a Kd value of 21.2 +/- 8.33 pM and a Bmax value of 2.02 +/- 0.52 fmol/mg protein. 10 microM of GTP gamma S significantly reduced the binding capacity, suggesting the possible G-protein coupling of the binding sites. Autoradiographic study showed that the labelling was mainly located in the cerebellar cortex. On comparison of the binding parameters from cerebellum of sudden infant death syndrome (SIDS) and non-SIDS infants, no significant change in binding capacity and binding affinity was detected. These findings suggest that the binding sites in cerebellum may not be related to the etiology of SIDS.

Functional reconstitution of ion channels from Paramecium cortex into artificial liposomes

Toward isolating channel proteins from Paramecium, we have explored the possibility of functionally reconstituting ion channels in an artificial system. Proteins from Paramecium cortex reconstituted with soybean azolectin retained several channels whose activities were readily registered under patch clamp. The most commonly encountered activities were three: (i) a 71-pS cation channel that opens at all voltages unless di- or trivalent cations were added to close them, (ii) a 40 pS monovalent cation channel, and (iii) a large-conductance channel that prefers anions and exhibits many subconductance states. These channels survived mild detergent treatments without observable functional alterations. The possible origin of these channels from internal membranes, the possible role of 71-pS channel in internal Ca2+ release, and the prospects of their purification are discussed.

A simple and efficient treatment for fingertip injuries

We have developed a simple, cheap and efficient method of management of fingertip injuries using an occlusive dressing--the fingertip cap (Hyphecan). The results of 156 fingertip injuries treated with this method demonstrate recovery to a near normal fingertip.

Foot biomechanics during walking and running

OBJECTIVE

To describe the anatomy and biomechanics of the foot and to explain how movement and gait are integrated in the foot during walking and running.

DESIGN

We review the anatomy and the biomechanical adaptations of the foot during walking and running.

MATERIAL AND METHODS

Illustrations are presented to depict these biomechanics.

RESULTS

The human foot is an intricate mechanism that cushions the body and adapts to uneven surfaces. It provides traction for movement, awareness of joint and body position for balance, and leverage for propulsion.

CONCLUSION

With an understanding of the factors discussed herein, clinicians will have more knowledge to evaluate foot problems.