Tumour lysis syndrome in a neonate with transient abnormal myelopoiesis.

BACKGROUND: Tumor lysis syndrome (TLS) is an oncological emergency associated with hematological malignancies or highly proliferative solid tumors, commonly after chemotherapy. It is rarely associated with transient abnormal myelopoiesis. OBSERVATION: We report a rare case of a neonate with transient abnormal myelopoiesis and tumor lysis syndrome, complicated with concomitant heart failure due to an underlying atrioventricular septal defect. Hyperhydration was contraindicated due to heart failure. The patient was managed conservatively with full recovery. CONCLUSION: Tumor lysis syndrome should be suspected in neonates with transient abnormal myelopoiesis with electrolyte abnormalities. Treatment options should be considered carefully for their risks and benefits.

Outcomes and Impact of Fragility Fracture among Geriatrics Patients who Underwent Hip Surgery in Hospital Kuala Lumpur.

Introduction: Fragility fractures are common in the elderly. It is associated with increased mortality, reduced mobility, and poorer quality of life. In addition, post-operative functional outcomes are limited locally. Materials and methods: A cross-sectional phone interview was conducted with elderly patients who underwent hip surgery or their caregivers between March 2019 and Feb 2020, at least six months after the operation. Results: A total of 137 cases were approached, and 77 subjects completed the interview (58.4%), among which 54/77 (70.1%) were female, and 66/77 (85.7%) were caregivers. The proportion of subjects who could ambulate independently dropped from 66/77, prior to fracture, to 17/77 post-surgery. We noted a significant deterioration in the modified Barthel Index from the median of 100 (IQR = 0) to 91 (IQR 25.5; p <0.001). There was also a significant decline in the self-perceived physical strength of 30% (IQR 30, p <0.001); and in the functionality of 35% (IQR40; p <0.001). A total of 48/77 (62.3%) returned to their original residence, while 5 cases (6.5%) were institutionalised, and 14/77 (18.2%) died prior to the survey. Thirty-six subjects reported additional costs in the care of patients, ranging from RM100 to RM6000 (USD25 to USD1450) per month. Conclusion: Decline in physical and functional status is closely related to the quality of life as the majority reported a poorer health status after the fracture. Although this study is limited by the small sample size, it provided insights into patients' experiences and household burdens. Hence, well-coordinated services and monitoring are important for better outcomes.

Biodiversity of orb-web spiders (family: araneidae) of buner valley, Pakistan / Biodiversidade de aranhas construtoras de teia (família: araneidae) do vale buner, Paquistão

The present research was carried out to explore the spider fauna of Buner valley with taxonomic study from February 2018 to January 2019. For this purpose samples were collected, four times at each month from 4 tehsils: Daggar, Gagra, Mandan and Totalai. Two methods were used, hand picking and sweep net for collection of samples. During day and night, three habitats, arid area, agriculture land and building area were search for collection. A total of 534 samples of spider were collected from four sampling sites, in which 379 were belonging to family Araniedae. After confirmation, the identified species were belonging to 8 genera (Neoscona, Argiope, Cyclosa, Araneus, Cyrtophora, Larinia, Erivoxia and Poltys) and 19 species. 18 of them were identified to specie level while a single specie to its generic level. The genus Neoscona was the dominant genus 26.31% having 5 species while the genus Argiope 21.05% is the second dominant having 4 species followed by Cyclosa 15.78% having 3 species followed by Cyrtophora and Araneus 10.52% having two species both. The Poltys and Larinia 5.26% are the rarest genera represent single-single specie both. Statistical analysis show that specie richness (D) = 5.77, Simpson index (1-D) = 0.87, Shannon index (H) = 2.33. Diversity of spiders was evenly distributed and calculated Evenness value was H/InS = 0.5408. There is also few atypical species and Fisher alpha estimate high value (Fisher α) = 4.42. Chao-1 estimated we have reported 22 species.

A presente pesquisa foi realizada para explorar a fauna de aranhas do vale Buner, em um estudo taxonômico realizado de fevereiro de 2018 a janeiro de 2019. Para esse fim, foram coletadas amostras, quatro vezes por mês, a partir de 4 subdistritos: Daggar, Gagra, Mandan e Totalai. Foram utilizados dois métodos, coleta manual e rede de varredura, para a obtenção das amostras. Durante o dia e a noite, foram pesquisados três habitats: área árida, área agrícola e área de construção. Foram coletadas 534 amostras de aranha em quatro locais de amostragem, sendo que 379 pertenciam à família Araneidae. Após a confirmação, as espécies identificadas pertenciam a 8 gêneros (Neoscona, Argiope, Cyclosa, Araneus, Cyrtophora, Larinia, Erivoxia e Poltys) e a 19 espécies (18 delas foram identificados em seu nível de espécie, enquanto uma única foi identificada em seu nível genérico). O gênero Neoscona foi dominante (26,31%), com 5 espécies, seguido pelos gêneros Argiope (21,05%), com 4 espécies, Cyclosa (15,78%), com 3 espécies, e Cyrtophora e Araneus (10,52%), com 2 espécies. Poltys e Larinia (5,26%) são os gêneros mais raros, representando a mesma espécie. A análise estatística mostrou que a riqueza de espécies (D) foi de 5,77, o índice de Simpson (1-D) foi de 0,87 e o índice de Shannon (H) foi de 2,33. A diversidade de aranhas foi distribuída uniformemente, e o valor calculado da uniformidade foi H / InS = 0,5408. Também existem poucas espécies atípicas, e o alfa de Fisher (Fisher α) estimou o valor de 4,42. Já Chao-1 estimou 22 espécies.

Challenging immunodominance of influenza-specific CD8+ T cell responses restricted by the risk-associated HLA-A*68:01 allomorph.

Although influenza viruses lead to severe illness in high-risk populations, host genetic factors associated with severe disease are largely unknown. As the HLA-A*68:01 allele can be linked to severe pandemic 2009-H1N1 disease, we investigate a potential impairment of HLA-A*68:01-restricted CD8+ T cells to mount robust responses. We elucidate the HLA-A*68:01+CD8+ T cell response directed toward an extended influenza-derived nucleoprotein (NP) peptide and show that only ~35% individuals have immunodominant A68/NP145+CD8+ T cell responses. Dissecting A68/NP145+CD8+ T cells in low vs. medium/high responders reveals that high responding donors have A68/NP145+CD8+ memory T cells with clonally expanded TCRαßs, while low-responders display A68/NP145+CD8+ T cells with predominantly naïve phenotypes and non-expanded TCRαßs. Single-cell index sorting and TCRαß analyses link expansion of A68/NP145+CD8+ T cells to their memory potential. Our study demonstrates the immunodominance potential of influenza-specific CD8+ T cells presented by a risk HLA-A*68:01 molecule and advocates for priming CD8+ T cell compartments in HLA-A*68:01-expressing individuals for establishment of pre-existing protective memory T cell pools.

Anxiety and depression in patients with haematological neoplasms in Malaysia.

BACKGROUND: It is not uncommon that anxiety and depression occur in patients with cancers, and past researches have shown that the quality of life of patients is negatively affected. This study aims to determine the prevalence of anxiety and depression of patients with haematological cancers in Malaysia and to investigate the possible association of these psychological symptoms with their quality of life. METHODS: This is a cross-sectional study where patients with haematological cancers attending two major hospitals were recruited. Anxiety and depression symptoms were assessed using the Hospital Anxiety and Depression scale (HADS). Quality of life (QoL) of these patients was measured using the European Organisation for Research and Treatment of Cancer quality of life questionnaire (EORTC QLQ C30). An overall summary QoL score in combination with financial difficulty score and global health score were used for analysis. RESULTS: A total of 319 patients were recruited. Thirty-three percent of patients had anxiety symptoms, 23.5% had depression symptoms. In summary the overall score of QoL is significantly lower in patients with higher scores for depression and anxiety, (p<0.05). Patients who exhibit anxiety symptoms were more frequently female, still undergoing treatment whereas patients who had higher depression scores were older and had acute leukemias or myeloproliferative neoplasms. Patients who have depression are significantly associated with a higher financial difficulty score, p<0.05. CONCLUSION: The poor quality of life in patients who have anxiety and depression should raise awareness amongst the health professions treating them so that additional support can be provided.

Influence of genetic polymorphisms of cytokine genes in the outcome of HLA-matched allogeneic stem cell transplantation in a South East Asian population.

Non-HLA gene polymorphisms have been shown to be associated with the risk of graft-versus-host disease (GVHD) and outcome of allogeneic haematopoietic stem cell transplantation (AHSCT). This study aims to investigate the role of IL6, TNFα, IL10, IL2 and IL12 gene polymorphisms in the outcome of AHSCT in a South East Asian population. A total of 67 patients and 59 donors who underwent HLA-identical matched sibling AHSCT were available for analysis. There was no significant association between the different cytokine genotypes of patients with the incidence and severity of acute GVHD. Patients with IL2 166∗T allele and patients who received donor stem cells who had IL2 166∗G allele appeared to have reduced incidence of cGVHD. Patients who received donor stem cells with IL12 1188∗C allele are found to be associated with better disease free survival. These results suggest a possible role of IL2 and IL12 gene polymorphisms in the outcome of AHSCT in a South East Asian population.

A hydrophobic area of the GABA ρ1 receptor containing phenylalanine 124 influences both receptor activation and deactivation.

Experimental evidence suggests that GABA ρ1 receptors are potential therapeutic targets for the treatment of a range of neurological conditions, including anxiety and sleep disorders. Homology modelling of the GABA ρ1 extracellular N-terminal domain has revealed a novel hydrophobic area that extends beyond, but not including the GABA-binding site. Phenylalanine 124 (F124) is predicted to be involved in maintaining the structural integrity of the orthosteric-binding site. We have assessed the activity of a series of GABA ρ1 receptors that incorporate a mutation at F124. Wild-type and mutant human GABA ρ1 subunits were expressed in Xenopus laevis oocytes and AD293 cells, and the pharmacology and kinetic properties of the receptors were measured using electrophysiological analysis. Mutation of F124 had minimal effect on receptor pharmacology. However, the rate of deactivation was significantly increased compared to wild type. This study provides further information about the role of residues within a novel hydrophobic area of the GABA ρ1 receptor. This knowledge can help future studies into the design of potent and subtype-selective ligands with therapeutic value.

Tsukamurella tyrosinosolvens intravascular catheter-related bacteremia in a haematology patient: a case report.

Tsukamurella spp. are a rare but important cause of intravascular catheter-related bacteremia in immunocompromised patients. The organism is an aerobic, Gram-positive, weakly acid-fast bacillus that is difficult to differentiate using standard laboratory methods from other aerobic actinomycetales such as Nocardia spp., Rhododoccus spp., Gordonia spp., and the rapid growing Mycobacterium spp. We report a case of Tsukamurella tyrosinosolvens catheter-related bacteremia in a 51-year-old haematology patient who responded to treatment with imipenem and subsequent line removal. 16srRNA sequencing allowed for the prompt identification of this organism.

Hypertrophic Cardiomyopathy: Prevalence, Hypertrophy Patterns, and Their Clinical and ECG Findings in a Hospital at Qatar.

BACKGROUND: Hypertrophic cardiomyopathy (HCM) is a genetic disease associated with risk of morbidity and sudden cardiac death. The prevalence, hypertrophy patterns, mode of presentations, and different ECG findings vary in different regions of the world. To date, no data is present regarding these variables in Qatar. PATIENTS AND METHODS: A retrospective, cross sectional, descriptive analysis of all patients referred for echocardiography study at Hamad General Hospital, Qatar. The study period was from January 2008 till December 2010. AIMS: To study 1) the prevalence of HCM, 2) the different patterns of hypertrophy, and 3) the clinical and ECG presentations in this population. RESULTS: Out of the 29,286 cases evaluated, 38 patients were found to have HCM (0.13%). Their clinical, ECG, and echocardiography findings were analyzed. Mean age was 47 y, 35 males (92%) and 3 females (8%). Four patterns of hypertrophy were described; 17 (44.7%) had septal hypertrophy alone, 6 (15.8%) had septal and other segments hypertrophy but sparing the apex, 10 (26.3%) had apical segments along with any other segment hypertrophy, and 5 (13.2%) had apical hypertrophy alone. No obstruction was found in 19 (50%), left ventricular outflow (LVO) tract obstruction was found in 13 (34%), and mid cavity obstruction (MCO) in 6 (16%). Twenty one (55.3%) patients were referred because of chest pain, 15 (39.5%) with palpitations, 15 (39.5%) with shortness of breath, and 5 (13.2%) with syncope. Nine patients (23.7%) were asymptomatic and were referred because of cardiac murmur during routine examination. ECG evidence of LV hypertrophy was found in 29 (76.3%). CONCLUSION: The prevalence of HCM in our population group is 0.13% with a male predominance (12:1). There was a diversity of clinical presentation, ECG abnormalities and patterns of LV hypertrophy among HCM patients.

Usage of emergency contraception between medical related and non-medical related students.

Teenagers and young adultshave the most risk of unplanned pregnancy, due to lack of awareness to see a family planning provider after unprotected sexual intercourse. In addition, nearly one in five physicians is reluctant to provide information regarding Emergency Contraception (EC) to women and this may contribute to their lack of awareness. This study was conducted to assess the knowledge, attitudes and practices regarding the use of EC between medical related students compared to non-medical related students. Data collection was done using questionnaires distributed among students in University College Cork (UCC). 93% of medically related students were aware of EC compared to only 73.5% of non-medically related students. Medical related students also were more aware about the mechanism of action and detailed knowledge of EC compared to the non-medical students. This study has proven that medically related students have more detailed knowledge regarding EC compared to non-medical related students. However, there was no significant difference noted regarding the attitude and practice between the two groups.

Identification of different type of polymers in plastics waste.

The main goal of this work was to develop and test advanced techniques for the instant identification of different type of polymers in post-consumer plastics. In order to accomplish this task, infrared (IR), X-ray diffraction (XRD), differential scanning calorimetric (DSC) and laser induced breakdown spectroscopic (LIBS) techniques were applied. The following six model plastics were identified in this study. Low-density polyethylene (LDPE), High-density polyethylene (HDPE), Polypropylenes (PP), Polystyrene (PS), Polyethylene terephthalate (PET) and Polyvinyl chloride (PVC) along with few randomly selected plastics waste such as water bottle and cap, water cups, yogurt container and coke bottle were studied. IR has shown the fingerprinting of polymer types present in plastics waste. The XRD analysis helps to provide characteristic spectral lines whose intensities vary with the type of each constituent polymer. The DSC method provided the different crystalline melting temperature, glass transition, and onset temperature for the peaks and the percent crystallinity data single out different polymers. The ratio of LIBS signals intensities of carbon and hydrogen atoms were employed for the finger printing of the different family of plastics. The combined use of IR, XRD, DSC and LIBS techniques yielded very useful and effective results for plastic waste management.

Pairing of heterochromatin in response to cellular stress.

We previously reported that exposure of human cells to DNA-damaging agents (X-rays and mitomycin C (MMC)) induces pairing of the homologous paracentromeric heterochromatin of chromosome 9 (9q12-13). Here, we show that UV irradiation and also heat shock treatment of human cells lead to similar effects. Since the various agents induce very different types and frequencies of damage to cellular constituents, the data suggest a general stress response as the underlying mechanism. Moreover, local UV irradiation experiments revealed that pairing of heterochromatin is an event that can be triggered without induction of DNA damage in the heterochromatic sequences. The repair deficient xeroderma pigmentosum cells (group F) previously shown to fail pairing after MMC displayed elevated pairing after heat shock treatment but not after UV exposure. Taken together, the present results indicate that pairing of heterochromatin following exposure to DNA-damaging agents is initiated by a general stress response and that the sensing of stress or the maintenance of the paired status of the heterochromatin might be dependent on DNA repair.

Mitomycin C-induced pairing of heterochromatin reflects initiation of DNA repair and chromatid exchange formation.

Chromatid interchanges induced by the DNA cross-linking agent mitomycin C (MMC) are over-represented in human chromosomes containing large heterochromatic regions. We found that nearly all exchange breakpoints of chromosome 9 are located within the paracentromeric heterochromatin and over 70% of exchanges involving chromosome 9 are between its homologues. We provide evidence that the required pairing of chromosome 9 heterochromatic regions occurs in G(0)/G(1) and S-phase cells as a result of an active cellular process initiated upon MMC treatment. By contrast, no pairing was observed for a euchromatic paracentromeric region of the equal-sized chromosome 8. The MMC-induced pairing of chromosome 9 heterochromatin is observed in a subset of cells; its percentage closely mimics the frequency of homologous interchanges found at metaphase. Moreover, the absence of pairing in cells derived from XPF patients correlates with an altered spectrum of MMC-induced exchanges. Together, the data suggest that the heterochromatin-specific pairing following MMC treatment reflects the initiation of DNA cross-link repair and the formation of exchanges.

Ionizing radiation-induced instant pairing of heterochromatin of homologous chromosomes in human cells.

Using fluorescence in situ hybridization with human band-specific DNA probes we examined the effect of ionizing radiation on the intra-nuclear localization of the heterochromatic region 9q12-->q13 and the euchromatic region 8p11.2 of similar sized chromosomes 9 and 8 respectively in confluent (G1) primary human fibroblasts. Microscopic analysis of the interphase nuclei revealed colocalization of the homologous heterochromatic regions from chromosome 9 in a proportion of cells directly after exposure to 4 Gy X-rays. The percentage of cells with paired chromosomes 9 gradually decreased to control levels during a period of one hour. No significant changes in localization were observed for chromosome 8. Using 2-D image analysis, radial and inter-homologue distances were measured for both chromosome bands. In unexposed cells, a random distribution of the chromosomes over the interphase nucleus was found. Directly after irradiation, the average inter-homologue distance decreased for chromosome 9 without alterations in radial distribution. The percentage of cells with inter-homologue distance <3 micro m increased from 11% in control cells to 25% in irradiated cells. In contrast, irradiation did not result in significant changes in the inter-homologue distance for chromosome 8. Colocalization of the heterochromatic regions of homologous chromosomes 9 was not observed in cells irradiated on ice. This observation, together with the time dependency of the colocalization, suggests an underlying active cellular process. The biological relevance of the observed homologous pairing remains unclear. It might be related to a homology dependent repair process of ionizing radiation induced DNA damage that is specific for heterochromatin. However, also other more general cellular responses to radiation-induced stress or change in chromatin organization might be responsible for the observed pairing of heterochromatic regions.

Steinstrasse: a comparison of incidence with and without J stenting and the effect of J stenting on subsequent management.

OBJECTIVE: To analyse the effect of ureteric stenting on the incidence of steinstrasse and its effects on the subsequent management of steinstrasse. PATIENTS AND METHODS: Four hundred adult patients with a unilateral stone burden (mean diameter 1.5-3.5 cm) were randomly allocated into two groups; in group 1, patients had a J stent inserted before extracorporeal shock wave lithotripsy (ESWL) and group 2 did not. Before randomization, the patients had normal renal function and no evidence of ureteric obstruction on intravenous urography. All patients underwent ESWL, with the shock waves delivered first to the most dependent part of the calculi. Patients who developed steinstrasse were identified and the effect of the size of the calculi and the presence of a J stent on the incidence and level of the steinstrasse, on the time of diagnosis, the size of the major stone fragment, associated presenting symptoms and effect on subsequent management were compared between the groups. RESULTS: Patients developed steinstrasse in both groups, with 12 (6%) and 26 (13%) in groups 1 and 2, respectively (significantly different, P<0.05). The incidence of steinstrasse depended on the size of the calculus, regardless of whether a J stent was present, being 2.6% and 56% for a burden of 1.5-2.0 cm and 3.1-3.5 cm, respectively (P<0.001). There was no difference in the presenting symptoms in the two groups. The steinstrasse was in the lower third of the ureter in eight of 12 patients in group 1 and in 16 of 26 (62%) in group 2. The steinstrasse resolved spontaneously in seven patients in group 1 and in 12 (46%) in group 2 (P<0.11). Similarly, J stenting had no effect on the subsequent treatment modalities to resolve steinstrasse. CONCLUSION: The use of J stenting before lithotripsy significantly lowers the incidence of steinstrasse in patients with a stone burden of 1.5-3.5 cm. The incidence of steinstrasse increases with the size of the calculi, whether or not a J stent is present; J stenting has no apparent effect on the mode of presentation or the subsequent management of steinstrasse.

Case-controlled review of Clostridium difficile-associated diarrhoea in southern Tasmania.

AIM: While the incidence of Clostridium difficile-associated diarrhoea (CDAD) has increased sharply over the last 15 years, its risk factors are still not well defined. The aim of this study was to review cases of CDAD at the major teaching hospital in Tasmania, Australia, to identify risk factors for CDAD and their association with prognosis. METHODS: A retrospective review of the medical records of adult patients admitted to the hospital between January 1994 and December 1996 was performed. Sixty-four patients who developed CDAD prior to or during their admission, and an additional 120 diarrhoea-free patients (the control group) were studied. An extensive range of demographic and clinical variables were recorded, and the differences between the control group and patients with CDAD were evaluated. RESULTS: The CDAD patients had a median age of 66 years (range 22-95 years), with females accounting for 52% of cases. There were no significant demographic differences from the control group. Identifiable risk factors for developing CDAD were severe underlying disease, renal impairment, exposure to antibiotics or antineoplastic agents, and the use of total parenteral nutrition or nasogastric feeding. Cephalosporins were the most frequently used antibiotics in both CDAD and control patients, with cefotaxime being the only antibiotic which was identified as being significantly associated with an increased risk of CDAD. The median length of diarrhoea episodes was 9 days (range 1-60 days). The mortality rate was 17.2%, and factors associated with a poor prognosis were older age, severe underlying disease, renal impairment and failure to treat with metronidazole or vancomycin. Delay in starting specific treatment and use of codeine were related to prolonged CDAD. CONCLUSION: CDAD is a growing contributor to hospital morbidity and costs. Severely ill patients with compromised immune function are particularly susceptible, with antibiotic use being a major risk factor. Prompt diagnosis and initiation of treatment are important factors in the improvement of prognosis.

Beta-glucuronidase and hyperbilirubinemia in breast-fed versus formula-fed babies.

Breast milk and formula milk and the corresponding serum samples from 20 breast-fed babies, 20 formula-fed babies, and their mothers were examined at 3 days of age for beta-glucuronidase enzyme. Serum indirect bilirubin levels were also examined for all the infants. Serum indirect bilirubin concentrations were significantly higher (p < 0.001) in breast-fed (4.87 +/- 2.4 mg/dl) than in formula-fed infants (1.04 +/- 0.5 mg/dl). beta-glucuronidase activity in formula milk was negligible, while that in human milk was considerable (468.26 +/- 220.8 Sigma units/ml) and was correlated (p < 0.05) with that in the serum of the breast-fed (66.13 +/- 18.1 Sigma units/ml) than in formula fed infants (52.08 +/- 11.9 Sigma units/ml) and a significant (p < 0.05) correlation was found between its serum level and serum indirect bilirubin in both breast and formula fed infants. Also in breast-fed infants serum bilirubin concentrations were related to beta-glucuronidase activity in breast milk (p < 0.05): Breast milk beta-glucuronidase--by facilitating intestinal reabsorption of bilirubin--seems to be an important factor in the neonatal hyperbilirubinemia of breast-fed babies.

Purification and characterization of phosphodiesterase (exonuclease) from Cerastes cerastes (Egyptian sand viper) venom.

A venom exonuclease 'phosphodiesterase' (E.C. 3.1.4.1) has been purified from Cerastes cerastes venom by a combination of gel filtration on Sephadex G-100 superfine and ion exchange chromatography on DEAE-Sepharose. The enzyme showed a single band on PAGE and SDS-PAGE and had a molecular weight of 110,000. The final preparation was purified 28 fold. It had no carbohydrate and it did not have protease or 5'-nucleotidase activities. Optimum temperature for enzyme activity was 56 degrees C. The enzyme was rapidly inactivated when pre-incubated above 40 degrees C. Energy of activation (Ea) was calculated to be 0.913. The optimum pH was 9.0. Cysteine, glutathione, dithiothreitol, 2-mercaptoethanol, ADP and AMP inhibited the enzyme. Cysteine caused a non-competitive inhibition, while ADP showed a competitive inhibition. EDTA at a concentration of 0.5 mM caused complete inhibition of the enzyme, which could be reversed by the addition of Ca2+ or Mn2+.

Further characterization of the anticoagulant proteinase, cerastase F-4 from Cerastes cerastes (Egyptian sand viper) venom.

A potent anticoagulant, cerastase F-4, was purified from the venom of Cerastes cerastes. The u.v. absorption spectrum revealed a relatively high tyrosine and low tryptophan content. The molar extension coefficient and E278(0.1%) were 19,400 and 0.84, respectively. The enzyme secondary structure, as studied by circular dichroism, showed 23.6% alpha-helix, 34% beta-sheets, 19% beta-turns and 32.5% random coils. When casein was used as a substrate the optimum pH was 10.0 and the Km was 1.45 g/l. Cerastase F-4 is a metallo-enzyme that contains one mole of Ca2+ and one mole of Zn2+ per mole of protein. It is not affected by phenylmethane sulfonylfluoride or soybean trypsin inhibitor, while it is completely inhibited by 0.5 mM EDTA or ethyleneglycol bis (beta-amino ethylether) N,N,N',N'-tetraacetic acid (EGTA). Ca2+, Mg2+ and Zn2+ partially activated the enzyme under different experimental conditions. Our results suggest that Ca2+ and Zn2+ may play a role in maintaining the structural and catalytic integrity of the enzyme.