Activation of hPAK65 by caspase cleavage induces some of the morphological and biochemical changes of apoptosis

Apoptosis is a highly regulated form of cell death, characterized by distinctive features such as cellular shrinkage and nuclear condensation. We demonstrate here that proteolytic activation of hPAK65, a p21-activated kinase, induces morphological changes and elicits apoptosis. hPAK65 is cleaved both in vitro and in vivo by caspases at a single site between the N-terminal regulatory p21-binding domain and the C-terminal kinase domain. The C-terminal cleavage product becomes activated, with a kinetic profile that parallels caspase activation during apoptosis. This C-terminal hPAK65 fragment also activates the c-Jun N-terminal kinase pathway in vivo. Microinjection or transfection of this truncated hPAK65 causes striking alterations in cellular and nuclear morphology, which subsequently promotes apoptosis in both CHO and Hela cells. Conversely, apoptosis is delayed in cells expressing a dominant-negative form of hPAK65. These findings provide a direct evidence that the activated form of hPAK65 generated by caspase cleavage is a proapoptotic effector that mediates morphological and biochemical changes seen in apoptosis.

CPAN, a human nuclease regulated by the caspase-sensitive inhibitor DFF45

Induction of apoptosis by death receptors such as Fas or tumour necrosis factor (TNF) R1 leads to distinct changes in cell morphology, activation of the caspase protease cascade, and the degradation of nuclear chromatin by activated nucleases. Here, we describe the purification and cDNA cloning of a novel 40 kDa endonuclease from Jurkat cells that is activated by caspases. This protein, designated caspase-activated nuclease (CPAN), is sufficient to degrade naked DNA and to induce apoptotic morphology and DNA fragmentation in naive nuclei. CPAN is highly homologous to a recently described mouse nuclease, CAD [1], and may represent the human homologue. Our data on the human cDNA as well as additional data on the mouse homologue suggest that a 30 amino-acid portion of the recently published mouse sequence [1] is incorrect. We show that the activity of human CPAN is regulated by DFF45 [2], an inhibitor necessary for CPAN expression and stabilization in an inactive state in living cells. Proteolytic cleavage of DFF45 by caspases in vitro leads to dissociation of DFF45 fragments from CPAN and activation of CPAN as an endonuclease. CPAN is a tightly regulated endonuclease with unique characteristics that might represent a distinctive family of endonucleases.

Conjugated linoleic acid and disease prevention: a review of current knowledge

Conjugated linoleic acid (CLA), a derivative of a fatty acid linoleic acid (LA), has been reported to decrease tumorigenesis in animals. CLA is unique because unlike most antioxidants which are components of plant products, it is present in food from animal sources such as dairy foods and meats. CLA concentrations in dairy products typically range from 2.9 to 8.92 mg/g fat of which the 9-cis, 11-trans isomer makes up to 73% to 93% of the total CLA. Low concentrations of CLA are found in human blood and tissues. In vitro results suggest that CLA is cytotoxic to MCF-7 cells and it inhibits the proliferation of human malignant melanoma and colorectal cancer cells. In animal studies, CLA has inhibited the development of mouse epidermal tumors, mouse forestomach cancer and rat mammary cancer. Hamsters fed CLA collectively had significantly reduced levels of plasma total cholesterol, non-high-density lipoprotein cholesterol, (combined very-low and low-density lipoprotein) and triglycerides with no effect on high-density lipoprotein cholesterol, as compared to controls. Dietary CLA modulated certain aspects of the immune defense but had no obvious effect on the growth of an established, aggressive mammary tumor in mice. It is now thought that CLA itself may not have anti-oxidant capabilities but may produce substances which protect cells from the detrimental effects of peroxides. There is, however, insufficient evidence from human epidemiological data, and very few of the animal studies have shown a dose-response relationship with the quantity of CLA feed and the extent of tumor growth. Further research with tumor models is needed to test the efficacy and utility of CLA in cancer and other disease prevention and form the basis of evaluating its effect in humans by observational studies and clinical trials.

Phenobarbital and diphenylhydantoin levels in neonates with seizures

Little information is available regarding appropriate plasma levels of anticonvulsant drugs in neonates. We determined the plasma levels of phenobarbital and diphenylhydantoin following initial administration and during maintenance therapy in 59 neonates with seizures. Following intravenous administration of 15 to 20 mg/kg, levels of 20.7 +/- 4.4 microgram/ml were achieved for phenobarbital and levels of 14.5 +/- 3 microgram/ml for DPH. Maintenance doses of 5 mg/kg of phenobarbital resulted in initial drug accumulation followed by more rapid elimination of the drug with increasing duration of exposure. Therapeutic plasma levels of DPH could not be achieved by oral administration in the neonate.

Cisplatin combination chemotherapy versus chlorambucil in advanced ovarian carcinoma: mature results of a randomized trial

A randomized study to compare the efficacy of combination chemotherapy (cisplatin, doxorubicin, cyclophosphamide: PACe) with chlorambucil (CB) in International Federation of Gynecology and Obstetrics (FIGO) stage III and IV ovarian carcinoma was conducted between May 1979 and October 1983. Patients failing initial CB were subsequently eligible for treatment with PACe. Eighty-nine patients were randomized and 85 were eligible for analysis; as of date, 72 of these patients have died. The majority of patients in this study had bulky residual disease after their initial laparotomy (76%). Complete response (CR) was documented by a second laparotomy after five cycles of combination therapy or 6 to 12 months alkylating agent therapy. The overall response rate (CR plus partial response [PR]) for the combination (PACe, 68%) was significantly higher (P = .0004) than that for the chlorambucil (CB, 26%). However, the median survival was not improved (PACe, 13 months; CB, 11 months) and the survival curves were not significantly different (log rank test P = .25). The results of this study are comparable to preliminary data reported from other similar randomized studies. PACe, as administered in this study, is not indicated as routine therapy in patients with bulky residual ovarian carcinoma.

Differential 3' polyadenylation of the Huntington disease gene results in two mRNA species with variable tissue expression

Recently a novel gene containing a CAG trinucleotide repeat that is expanded on HD chromosomes has been identified(1). This gene was shown to detect a single transcript of 10-11 kb by RNA hybridization. We have however, previously identified three cDNAs which are part of the same gene that have been shown to detect two distinct transcripts of 10 kb and one that is significantly larger(2,3). These different mRNA species could be due to use of alternate transcription start sites, alternate splicing or selection of different polyadenylation sites. We have identified cDNA clones spanning the HD gene including two (HD12 and HD14) that share identical protein coding sequences but differ in size and sequence of their 3' untranslated region. HD14 has 3,360 base pairs of additional sequence distal to the previously published 3' end (1). RNA hybridization has revealed that the larger 13.7 kb fragment is the predominant transcript in human brain. cDNA fragments unique to HD14 detected only the larger transcript. Sequence analysis identified two different putative polyadenylation sequences at position 10,326 and 13,645 of the HD14 cDNA. These findings indicate that the two observed mRNA species originate from a single gene and that differential polyadenylation leads to transcripts of different size. The relative increased abundance of the larger transcript in human brain may provide some insights into the mechanism by which a widely expressed gene may exert tissue specific effects.

Sequence of the murine Huntington disease gene: evidence for conservation, alternate splicing and polymorphism in a triplet (CCG) repeat [corrected]

Huntington disease (HD) is associated with significant expansion of a CAG trinucleotide repeat within a novel gene. However, no clues to the function of this gene were apparent by sequence alignment to other proteins. We have therefore sought to identify the mouse gene (hd) as a first step in the development of an animal model for HD to provide insights into the molecular pathogenesis of this disease. Here, we report the sequencing of cDNA clones spanning 9,992 nucleotides encoding the murine HD homologue (hd), which exhibits 90% peptide sequence identity, including conservation of the CAG and adjacent CCG repeats. In addition, we show that the CCG is polymorphic in the mouse. Sequence analysis provides strong evidence that the first in frame methionine 5' to the CAG repeat, is the translational start site, for both the mouse and human transcript. As in human, the gene appears expressed in the mouse as 2 large transcripts. We observe evidence for alternate splicing of the hd gene in mouse tissues which would predict two protein products differing by 480 amino acid residues with a molecular mass difference of approximately 54 kilodaltons.

Different meanings of respite: a study of parents, nurses and social workers caring for children with complex needs

AIM

To examine the meaning of respite care to parents of children with complex conditions and providers.

METHODS

In-depth interviews, participant observation and document review were used to collect data from nineteen mothers and seven fathers of children between the ages of 8 and 16 years who required complex care and from their respite providers, including thirteen nurses, and four social workers from three counties in North-west England.

RESULTS

Parents described three categories of respite: short breaks provided by the extended family or friends, short breaks (3-4 h) by an outside agency, and overnight respite outside of home. They highly valued overnight respite outside the home. There was some overlap but also notable differences between parents' and providers' categorizations of respite care and the value attached to different forms of respite provision. Parents and nurses valued overnight respite outside the home unlike social workers who preferred to provide respite without separating children from their families.

DISCUSSION

Appropriate provision of respite care and communication with parents requires understanding of the meaning of respite to parents. The meanings attached to respite care by parents and providers should be considered in attempts to understand and address problems of inappropriate provision and/or dissatisfaction with respite services.

O6-methylguanine-DNA methyltransferase-defective human cell mutant: O6-methylguanine, DNA strand breaks and cytotoxicity

We have isolated an isogenic O6-methylguanine (O6-MeG)-DNA methyltransferase-defective mutant from a HeLa cell line. This mutant exhibits excess DNA strand breaks and considerable cytotoxicity after N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) treatment. The increased frequency of strand breaks after MNNG treatment was not abolished by DNA synthesis inhibitors. We propose that the presence of unrepaired O6-MeG lesions leads to excess strand breaks and these, in turn, are mainly responsible for the cytotoxicity.

"Another thing to live for": Supporting HCV treatment and cure among Indigenous people impacted by substance use in Canadian cities

BACKGROUND

Colonization and colonial systems have led to the overrepresentation of Indigenous people impacted by substance use and HCV infection in Canada. It is critical to ensure Indigenous people's equitable access to new direct acting antiviral HCV treatments (DAAs). Identifying culturally-safe, healing-centered approaches that support the wellbeing of Indigenous people living with HCV is an essential step toward this goal. We listened to the stories and perspectives of HCV-affected Indigenous people and HCV treatment providers with the aim of providing pragmatic recommendations for decolonizing HCV care.

METHODS

Forty-five semi-structured interviews were carried out with Indigenous participants affected by HCV from the Cedar Project (n = 20, British Columbia (BC)) and the Canadian Coinfection Cohort (n = 25, BC; Ontario (ON); Saskatchewan (SK)). In addition, 10 HCV treatment providers were interviewed (n = 4 BC, n = 4 ON, n = 2 SK). Interpretive description identified themes to inform clinical approaches and public health HCV care. Themes and related recommendations were validated by Indigenous health experts and Indigenous participants prior to coding and re-contextualization.

RESULTS

Taken together, participants' stories and perceptions were interpreted to coalesce into three overarching and interdependent themes representing their recommendations. First: treatment providers must understand and accept colonization as a determinant of health and wellness among HCV-affected Indigenous people, including ongoing cycles of child apprehension and discrimination within the healthcare system. Second: consistently safe attitudes and actions create trust within HCV treatment provider-patient relationships and open opportunities for engagement into care. Third: treatment providers who identify, build, and strengthen circles of care will have greater success engaging HCV-affected Indigenous people who have used drugs into care.

CONCLUSION

There are several pragmatic ways to integrate Truth and Reconciliation as well as Indigenous concepts of whole-person wellness into the HCV cascade of care. By doing so, HCV treatment providers have an opportunity to create greater equity and support long-term wellness of Indigenous patients.

Pain after laparoscopy: an observational study and a randomized trial of local anesthetic

Our objective was to determine if local anesthesia reduces pain after a laparoscopy. Eighty women were assigned randomly 10 ml of 0.5% bupivacaine or 0.9% saline flushed over the peritoneal folds and into the abdominal wall after laparoscopy under general anesthesia. Pain scores from the deep abdomen, skin, shoulder, and back were collected 30 min, 2 h, 4 h, and the day following laparoscopy. Pain scores also were correlated with patients' height, weight, operative findings, surgical technique and procedure, and volume of gas insufflated into the abdomen. Bupivacaine has a small effect on abdominal and skin pain 2 h after surgery (p = 0.01) but has no effect on shoulder or back discomfort. Women who have been sterilized, have not had previous abdominal surgery, or have evidence of old pelvic inflammation report more postoperative backache and deep abdominal pain but no greater skin or shoulder discomfort. Weight, height, whether the abdominal wall was picked up, and the volume of gas used to insufflate the abdomen are independent of all postoperative pain scores. Local anaesthetic instilled down the laparoscopy trocar reduces skin discomfort 2 h after surgery, but this beneficial effect is small compared with other factors influencing pain after laparoscopy.

The interaction of yeast RNA polymerase I and Cibacron blue F3GA

The interaction between yeast RNA polymerase I and Cibacron blue F3GA has been studied by difference spectrophotometry and column chromatography. The enzyme is reversibly inhibited by the dye. 50% inhibition is obtained with 7.5 x 10(-6) M Cibacron blue. 1 mol Cibacron blue binds per mol enzyme. This interaction, which is inhibited by salt, occurs at a site different from the active site. When RNA polymerase I is chromatographed in Blue dextran-Sepharose columns, two polypeptides, of 48 000 and 36 000 daltons, are dissociated from the enzyme. The resulting enzyme is completely inactive, ATP (5 mM) present in the elution buffer prevents both the dissociation of the polypeptides and the inactivation of the enzyme.

Isolation, characterization and complementation analysis of nirB mutants of Escherichia coli deficient only in NADH-dependent nitrite reductase activity

Mutants have been isolated which lack NADH-dependent nitrite reductase activity but retain NADPH-dependent sulphite reductase and formate hydrogenlyase activities. These NirB- strains synthesize cytochrome c552 and grow normally on anaerobic glycerol-fumarate plates. The defects map in a gene, nirB, which is extremely close to cysG, the gene order being crp, nirB, cysG, aroB. Complementation studies established that nirB+ and cysG+ can be expressed independently. The data strongly suggest that nirB is the structural gene for the 88 kDal NADH-dependent nitrite oxidoreductase apoprotein (EC 1.6.6.4). The nirB gene is apparently defective in the previously described nirD mutant, LCB82. The nirH mutant, LCB197, was unable to use formate as electron donor for nitrite reduction, but NADH-dependent nitrite reductase was extremely active in this strain and a normal content of cytochrome c552 was detected. Strains carrying a nirE, nirF or nirG mutation gave normal rates of nitrite reduction by glucose, formate or NADH.

Classification of individuals based on sparse representation of brain cognitive patterns: a functional MRI study

Many neurological disorders can change patterns of brain activity observed in functional imaging studies. These functional differences may be useful for classification of individuals into diagnostic categories. However, due to the high dimensionality of the input feature space and small set of subjects that are usually available, classification based on fMRI data is not trivial. Here, we evaluate the use of a Sparse Representation Analysis method within a Fisher Linear Discriminant (FLD) classification method, taking functional patterns characteristic of different cognitive tasks as the data input. As a test dataset, with a clear 'gold-standard' classification, we attempt to classify individuals as young, or older, based only on functional activation patterns in a speech listening task. Thirty two young (age: 19-26) and older (age: 57-73) adults (16 each) were scanned while listening to noise and to sentences degraded with noise, half of which contained meaningful context that could be used to enhance intelligibility. Different functional contrast images were used within K-SVD to generate basis activation sources and their corresponding sparse modulation profiles. Sparse modulation profiles were used in a FLD framework to classify individuals into the young and older categories. The results demonstrate the feasibility of the general approach, and confirm the potential applicability of the proposed method for real-world diagnostic problems.

Influence of microscopic residual disease on survival for stage IB and IIA carcinoma of the cervix following intracavitary irradiation

From 1977 to 1982, 102 patients with Stage IB and IIA carcinoma of the cervix underwent preoperative intracavitary caesium irradiation followed by radical hysterectomy and pelvic lymphadenectomy at the Wessex Radiotherapy Centre. The actuarial 5-year survival rate for Stage IB is 80% and for Stage IIA is 62%. Patients who had microscopic residual disease in the hysterectomy specimen and negative nodes showed an actuarial 10-year survival rate of 62% as opposed to 82% in patients with no residual disease and negative nodes (P less than 0.05).

Alveolar soft-part sarcoma of the orbit

Alveolar soft-part sarcoma is a malignant soft tissue neoplasm that involves mainly the deep soft tissues of the extremities, particularly the thighs and the buttock. Involvement of the orbit is uncommon. We describe a young child with such a tumor and illustrate the characteristic features.

Abnormal laboratory test values during ceftriaxone therapy

Laboratory tests were conducted to determine the safety of ceftriaxone during clinical use. Laboratory test values were evaluated in 153 individual clinical studies. A total of 2,640 patients received ceftriaxone at various doses, ranging from a single dose to six weeks of administration. The most frequently encountered laboratory test abnormalities in the overall population were hematologic (14.4 percent), hepatic (5 percent), and renal (1.4 percent). When analyzed separately, the incidences of hematologic, hepatic, and renal laboratory test abnormalities in the pediatric population were 30.8, 7.7, and 0.7 percent, respectively. The incidence of abnormal laboratory test results for once- and twice-daily drug administration was comparable. There were no significant differences except for the frequency of thrombocytosis for which the incidence for once-daily administration was 1.8 percent and for twice-daily administration 5.3 percent. The incidence of abnormal laboratory test values during ceftriaxone therapy (19.0 percent) was comparable to that observed with the cephalosporins (18.3 percent) and other comparative drugs used in these studies. Ceftriaxone is at least as safe and as well tolerated as other currently available antimicrobial agents used in the therapy of serious bacterial infections.