Advanced Systemic Mastocytosis with associated haematological neoplasm: Treatment with avapritinib can facilitate successful bridge to allogeneic haematopoietic cell transplant

Advanced systemic mastocytosis (AdvSM) is a rare, life-limiting mast cell (MC) neoplasm, with approximately 70% patients having an associated haematological neoplasm (AHN). Avapritinib, a selective tyrosine kinase inhibitor targeting KIT D816V, has shown potent activity translating clinically into durable responses in the phase 1 EXPLORER (NCT02561988) and phase 2 PATHFINDER (NCT03580655) studies. We report three patients with AdvSM-AHN on avapritinib who achieved complete remission (CR) of SM and were successfully bridged to allogeneic haematopoietic cell transplant (allo-HCT). Two cases additionally highlight the risk of clonal evolution within the AHN component and requirement for close monitoring while on targeted therapy.

Cost effectiveness of using Faecal Immunochemical Testing (FIT) as an initial diagnostic investigation for patients with lower gastrointestinal symptoms suggestive of malignancy

Background

There has been an increase in the numbers of patients presenting to primary care with suspected colorectal malignancy and subsequently an increase in demand for endoscopy. This study aims to forecast the cost of faecal immunochemical testing (FIT) compared to conventional diagnostic tests as a primary investigation for patients with symptoms suggestive of colorectal malignancy.

Methods

Retrospectively, 1950 patients with symptoms suggestive of colorectal malignancy who were referred through primary care and underwent investigations through standard endoscopic evaluation were included. These patients were used to forecast the cost of faecal immunochemical testing creating theoretical data for sensitivity and specificity. Outcome measures included: the number of investigations under current protocol; cost of current investigations; number of predicted false negatives and false positives and positive/negative predictive values using current sensitivity data for FIT; the cost forecast of using FIT as the primary investigation for colorectal malignancy.

Results

Median age was 65 (IQR 47–82) with 43.7% male and 56.3% female. A total of 1950 investigations were carried out with a diagnostic yield of 26 cancers (18 colon, 8 rectal), 138 polyps and 29 high risk adenomas (HGD ±  > 10 mm). In total, £713,948 was spent on the investigations. The commonest investigation was colonoscopy totalling £533,169. The total cost per cancer diagnosis was £27,459. Sensitivity (92.1% CI 86.9–95.3) and specificity (85.8% CI 78.3–90.1) for FIT in colorectal cancer was taken from NICE and was costed via the manufacturer(s). The projected total cost of FIT for the same population using a ≥ 4 μg haemoglobin cut off was £415,680 (£15,554 per cancer). The total cost of high-risk polyps using ≥ 4 μg cut off was £404,427 (sensitivity 71.2% CI 60.5–87.2, specificity 79.8%CI 76.1–83.7) or £13,945 per polyp.

Conclusions

FIT is a cheaper and effective alternative test with the potential to replace current expensive methods. The forecast is based on the limited data available for sensitivity/specificity in the current literature. FIT has now been commenced for symptomatic patients in the UK and therefore sensitivity may change in the future.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12875-021-01435-7.

Critical Incidents in a Multidisciplinary Intensive Care Unit

We aimed to determine the type and frequency of critical incidents in a multidisciplinary intensive care unit, to determine outcomes consequent to these incidents and to devise corrective strategies.

Prospectively collected data on critical incidents during a 33-month period were analysed. In all, 1918 patients were admitted to the unit during the study period. Each incident was analysed in detail. A system-based corrective strategy was sought for and implemented as appropriate.

In these patients, 280 critical incidents were reported during the study period, resulting in 3.4 incidents per 100 patient days. Airway-related incidents were the most frequent (32.8%) followed by line-related (21.8%) and drug-related (15%) incidents. Thirty-two incidents (11.4%) led to adverse outcomes. There were four deaths that occurred as a direct consequence of or contributed to by the incident, all due to airway-related incidents. A major physiological change occurred in 3.6% of incidents, while 6.4% of incidents resulted in a minor physiological change. Critical incidents were common in our multidisciplinary ICU, although adverse outcomes were rare.

Modulation of mitochondrial function by the microbiome metabolite propionic acid in autism and control cell lines

Propionic acid (PPA) is a ubiquitous short-chain fatty acid, which is a major fermentation product of the enteric microbiome. PPA is a normal intermediate of metabolism and is found in foods, either naturally or as a preservative. PPA and its derivatives have been implicated in both health and disease. Whereas PPA is an energy substrate and has many proposed beneficial effects, it is also associated with human disorders involving mitochondrial dysfunction, including propionic acidemia and autism spectrum disorders (ASDs). We aimed to investigate the dichotomy between the health and disease effects of PPA by measuring mitochondrial function in ASD and age- and gender-matched control lymphoblastoid cell lines (LCLs) following incubation with PPA at several concentrations and durations both with and without an in vitro increase in reactive oxygen species (ROS). Mitochondrial function was optimally increased at particular exposure durations and concentrations of PPA with ASD LCLs, demonstrating a greater enhancement. In contrast, increasing ROS negated the positive PPA effect with the ASD LCLs, showing a greater detriment. These data demonstrate that enteric microbiome metabolites such as PPA can have both beneficial and toxic effects on mitochondrial function, depending on concentration, exposure duration and microenvironment redox state with these effects amplified in LCLs derived from individuals with ASD. As PPA, as well as enteric bacteria, which produce PPA, have been implicated in a wide variety of diseases, including ASD, diabetes, obesity and inflammatory diseases, insight into this metabolic modulator from the host microbiome may have wide applications for both health and disease.

Real-time ultrasound guided percutaneous dilatational tracheostomy with and without bronchoscopic control: an observational study

BACKGROUND

Real-time ultrasound guidance may enable precise introducer needle and guidewire insertion during percutaneous dilatational tracheostomy (PDT). However, the safety of PDT done solely under ultrasound guidance has not been compared to additional bronchoscopic confirmation. We aimed to compare the efficacy, incidence of complications and procedural times of real-time ultrasound guided PDTs done with and without bronchoscopic confirmation.

METHODS

We analysed all bedside PDTs performed over an 18 month period. On transverse view, the introducer needle was inserted under real time guidance into the chosen interspace. The interspace of guidewire entry was confirmed on longitudinal view. In the bronchoscope group, needle and guidewire position within the tracheal lumen were confirmed by bronchoscopy.

RESULTS

We performed 177 PDTs under ultrasound guidance during the study period - 95 with and 82 without bronchoscopic confirmation. The introducer needle was inserted at the desired level on the first attempt in 81.4% of instances with no difference between groups (77.9% vs. 85.4%, P=0.6). Introducer needle entry between the first and third tracheal cartilages did not differ between groups (90.5% vs. 92.7%, P=0.6). Procedural times were longer in the bronchoscope group (13.9 min vs. 10.7 min, P<0.0001). There were more episodes of fall in oxygen saturation below 90% in the bronchoscope group (16.8% vs. 3.7%, P=0.006). Minor bleeding occurred in 6.2% of cases and did not differ between groups.

CONCLUSION

Ultrasound guidance for PDT may be equally safe, even without bronchoscopic confirmation; the incidence of hypoxic episodes may be less and the procedure can be performed in less time.

Critically ill patients with 2009 H1N1 infection in an Indian ICU

Background and Aims:

The 2009 pandemic influenza A (H1N1) has taken its toll across most parts of India. We aimed to study its epidemiology, clinical characteristics and outcomes from an Indian multidisciplinary intensive care unit (ICU).

Materials and Methods:

All patients admitted to our ICU with a flu-like illness and who tested positive for the 2009 H1N1 by reverse -transcriptase polymerase- chain -reaction assay during a 3 month period were prospectively studied.

Results:

Thirty one patients were admitted to the ICU during the study period. Patients were in the younger age group with a median age of 35 years (IQR: 28.2-42.8). Obesity was the commonest risk factor. Twenty six patients (83.9%) required ventilator support; the median duration of ventilator support was 10 days (IQR: 4-22). Severe hypoxemia was the predominant feature in all patients. Circulatory failure requiring vasopressors occurred in 18 (58.1%) patients and acute kidney injury in 6 (3.2%) patients. Twenty six patients were alive at the end of 28 days; subsequently all except one were discharged. The median duration of hospital stay was 15 (IQR: 8-22.5) days. Increasing APACHE II scores were associated with an increased risk of death (Hazard Ratio: 1.1; CI: 1.08 -1.2; P = 0.04). Mean tidal volumes in non-survivors were significantly lower; this was related to poor lung compliance in this group.

Conclusions:

2009 H1N1 infection caused severe disease in relatively young patients without significant co-morbidities, characterized by severe hypoxemia and the requirement for prolonged mechanical ventilation. Extra-pulmonary organ failure included circulatory and renal failure.

Fatal aluminium phosphide poisoning due to myocardial depression refractory to high dose inotropic support and intra-aortic balloon counterpulsation

We report a case of aluminium phosphide poisioning that presented to us with refractory myocardial depression. This patient developed worsening circulatory failure that did not respond to inotropic or vasopressor support and intra-aortic balloon counterpulsation. She went on to develop progressive metabolic acidosis, renal failure and died within 48 hours of admission to the intensive care unit.

Ruptured hydatid cyst masquerading as tension pneumothorax

We report a 35-year-old man who presented to us with features suggestive of a tension pneumothorax. However insertion of a chest tube did not result in any signs of improvement. Further investigation demonstrated that he had a ruptured hydatid cyst. He underwent an emergency thoractomy and excision of the cyst. Ruptured hydatid cyst should be considered as a possibility in patients who present with sudden onset respiratory distress and hypoxia in geographical areas where the disease may be prevalent.

Factors affecting the nasal carriage of methicillin-resistant Staphylococcus aureus in human immunodeficiency virus-infected patients

Human immunodeficiency virus-infected patients attending skin outpatient department were studied for nasal carriage of methicillin-resistant Staphylococcus aureus (MRSA) and associated factors affecting nasal colonization. Nasal swabs were used for isolation of S. aureus. MRSA were detected by agar screen and agar dilution methods. Careful examination for dermatoses was carried out. Forty-six of the 60 (76.67%) outpatients with HIV infection were colonized with S. aureus in the anterior nares. Significant number of S. aureus carriers were in the 31-40 year age group. Methicillin resistance was found in eight (17.39%) isolates. Of the 46 S. aureus strains, 29 (63%) were resistant to erythromycin, 69.5% to co-trimoxazole and 41.3% to ciprofloxacin. Co-trimoxazole use was found to be a risk factor for S. aureus carriage ( P = 0.0214) but not for methicillin resistance. Hospital stay for more than 10 days was a risk factor for methicillin resistance whereas stay for more than 25 days was found to be a highly significant risk factor. Dermatophytosis and herpes simplex virus infection were other risk factors for nasal carriage of S. aureus.

Jaggery: an avoidable cause of severe, deadly pediatric burns

BACKGROUND

Jaggery is the non-industrial refinement of sugar cane into a sugar product. Sugar cane cultivation, harvest and refinement are central aspects of rural Indian life.

METHODS

We present a retrospective review of pediatric burns at a single institution in Southern India, drawing special attention to scald burns incurred when young children fall into the cauldron of boiling jaggery. Descriptive statistics comparing children burned by jaggery and children burned by other mechanisms were performed. Multivariable logistic regression including burn size and mechanism of burn (jaggery and non-jaggery) was performed to determine the increased risk of death when burned by jaggery.

RESULTS

Children burned by jaggery immersions are older, more likely male, and have larger burns. They have longer hospital stays, more operations, and are more likely to die. When controlling for age, gender, size of burn, and mechanism, jaggery exposure was associated with a higher mortality.

DISCUSSION

Jaggery burns are deadly, devastating burns which could be prevented. While jaggery and sugar cane production can lead to economic independence for rural Indian villages, the cost it exacts from burns and death to the youngest and most vulnerable children must be addressed and prevented.

Y-duplication of the male urethra: use of anterior anorectal wall for posterior urethral lengthening

We have approached two patients with Y-duplication of the male urethra by a new two-staged technique to provide better results. A strip of anterior anorectal wall in continuity with the posterior urethra was used for posterior urethral lengthening and a tubed pedicled prepucial flap was used to reconstruct the anterior urethra without using the native urethra. This was done under a covering colostomy. After a gap of 6 months to allow for healing of the anorectum and to ensure adequate functioning of the perineal neourethra, second stage reconstruction was done using buried scrotal tube for the mid urethra along with colostomy closure. On follow-up at 8 and 12 months, respectively, both children were well with no stricture or fistula. There was normal anal continence and no stenosis. This technique tackles the problem in Y-duplication of the male urethra of lengthening the posterior urethral channel, which is often difficult to bring to the anterior half of the perineum especially if the opening is high up in the anorectum (case 2).

Differential control of eosinophil survival by glucocorticoids

Glucocorticoids are effective drugs for eosinophil-related disorders, such as asthma and allergy. Previous studies have demonstrated that glucocorticoids increase eosinophil apoptosis and block the survival effect of submaximal concentrations of interleukin-5 (IL-5). We investigated the effect of glucocorticoids on eosinophil survival in the presence of a higher concentration of IL-5 (1 ng/ml), comparable to IL-5 levels in bronchoalveolar lavage and sputum specimens from patients with asthma. In contrast to incubation in the presence of submaximal concentrations of IL-5, the addition of dexamethasone (DEX) to media containing 1 ng/ml IL-5 led to a significant increase in eosinophil cell viability from 58 +/- 6.9% to 87 +/- 2.4% ( p < 0.005) after 72 hours in culture. We found that RU486 blocked the DEX effect on cell viability confirming that glucocorticoid receptor functions are required. We investigated the possibility that the glucocorticoid enhancement of eosinophil survival may be due to an effect on IL-5 receptor expression. Our results show that the IL-5 associated decrease in IL-5 receptor alpha-subunit expression was blocked significantly after 24 hrs in culture with media containing IL-5 plus DEX compared to IL-5 alone. It is tempting to speculate that the observed glucocorticoid enhancement of eosinophil survival in the presence of elevated concentrations of IL-5 could be a mechanism that contributes to glucocorticoid resistance in asthma.

Smoking behaviour among arts student of a college in Mangalore, Dakshina Kannada

176 Arts students out of 450 students doing their under-graduation in an age range of 17 to 24 years returned a questionnaire designed to test their level of knowledge about smoking, attitude towards smoking and practice of smoking. 96.6% of the respondents were aware of the injurious nature of smoking. Potential to induce lung cancer was known by 93.2% of them, but only 34.1% knew it was a factor for GI malignancy. A higher proportion of males had good knowledge whereas females had moderate knowledge (p = 0.04). The incidence of smoking was 33.1%. A higher proportion of smokers chewed pan and consumed supari. 68.2% of smokers wished to quit smoking. Easy availability (47.7%) and influence of friends (34.1%) were the predominant reasons to smoke. Interestingly, 48% of males felt that smoking women had appeal. Anti smoking campaigns in addition to provision of information has to focus towards a change in attitude to smoking.

Pulmonary lipoblastoma: a case report

We report a case of pulmonary lipoblastoma in a 2-year-old child. This pathology has not been previously reported in the English literature.

Pneumothorax preceding pulmonary blastoma in a child

Serial plain radiographic, ultrasound and CT findings of an unusual case of pulmonary blastoma are described with a review of the literature.

Bilateral high loop ureterostomy in the primary management of posterior urethral valves in a developing country

Of 200 consecutive cases of posterior urethral valves (PUV) managed in a single institution, 26 underwent bilateral high loop ureterostomy (BU) as their first operative intervention. Indications for BU were persistently raised serum creatinine levels after bladder drainage, severe urosepsis, and urinary ascites, especially in a neonate or infant. After a median period of 1 year of diversion, the serum creatinine fell from a median value of 2.5 to 0.6 mg%. Twelve cases have been fully undiverted without deleterious effects (median serum creatinine level 0.5 mg%). Three patients died. Of the 14 renal units with documented persistent vesicoureteric reflux at the time of undiversion, only 1 has been reimplanted. One child has undergone bladder augmentation.

Pneumonostomy in the surgical management of bilateral hydatid cysts of the lung

During the period 1994-1998, three patients with bilateral hydatid cysts of the lung (HCL) underwent operative removal of the cysts. In three of the six lungs operated upon the conventional technique was used: after removal of the cyst and suture closure of bronchial leaks, the chest was closed with an intercostal drainage tube. Two of these patients developed bronchopleural fistulae requiring rethoracotomy and prolonged hospital stays. The other three lungs were operated upon using the pneumonostomy technique: after excision of the cyst a separate catheter is fixed within the residual lung cavity and brought out through the adjacent chest wall, effectively marsupialising the residual cavity to the atmosphere. All these patients had an uneventful postoperative recovery. We conclude that the pneumonostomy technique is a very useful method of treating HCL surgically, especially when the cysts are bilateral and complicated.

rhomboid and Star interact synergistically to promote EGFR/MAPK signaling during Drosophila wing vein development

Genes of the ventrolateral group in Drosophila are dedicated to developmental regulation of Egfr signaling in multiple processes including wing vein development. Among these genes, Egfr encodes the Drosophila EGF-Receptor, spitz (spi) and vein (vn) encode EGF-related ligands, and rhomboid (rho) and Star (S) encode membrane proteins. In this study, we show that rho-mediated hyperactivation of the EGFR/MAPK pathway is required for vein formation throughout late larval and early pupal development. Consistent with this observation, rho activity is necessary and sufficient to activate MAPK in vein primordium during late larval and early pupal stages. Epistasis studies using a dominant negative version of Egfr and a ligand-independent activated form of Egfr suggest that rho acts upstream of the receptor. We show that rho and S function in a common aspect of vein development since loss-of-function clones of rho or S result in nearly identical non-autonomous loss-of-vein phenotypes. Furthermore, mis-expression of rho and S in wild-type and mutant backgrounds reveals that these genes function in a synergistic and co-dependent manner. In contrast, spi does not play an essential role in the wing. These data indicate that rho and S act in concert, but independently of spi, to promote vein development through the EGFR/MAPK signaling pathway.

Torted ovarian cyst with lethal bleeding diathesis in an infant

We report a 9-month-old infant with a torted ovarian cyst who presented with an acute consumptive coagulopathy (CC) with lethal outcome. That ischemic tissue can act as a trigger for a CC is well-known, but we did not find any report of a torted ovarian cyst causing a coagulopathy in the pediatric literature. This potential complication constitutes one more reason for the prompt surgical removal of torted ovarian cysts in infants.

Growth and neurodevelopmental outcome in extremely-low-birth-weight infants after laparotomy

Twenty-one extremely-low-birth-weight (ELBW) and premature infants (<29 weeks' gestation and/or <1,000 g) underwent emergency laparotomy for acute intra-abdominal pathology (necrotising enterocolitis [NEC] 16, other bowel pathology 5) during the 4-year period from 1990 to 1993; 11 died. The neurodevelopmental outcome of the 10 survivors was assessed and compared with 20 living, otherwise normal controls matched for gestational age, birth weight, and year of birth to asses the effect of the abdominal event on quality of survival. Those who survived after laparotomy had a worse neurodevelopmental outcome than controls (P < 0.05). During this period, we also compared 24 infants in the ELBW category who developed NEC but did not require a laparotomy with the 16 ELBW infants with NEC who required a laparotomy. Those who required a laparotomy had worse disease and had significantly worse neurodevelopmental outcomes (P < 0.01). ELBW and premature infants who have acute intra-abdominal pathology requiring a laparotomy are thus at increased risk of neurodevelopmental problems and poor growth. Close long-term follow-up is important, and the families of such infants should be made aware before surgery of the increased risk the abdominal event has on their babies' developmental outcome if they survive.

Varied presentations of unilateral lung hypoplasia and agenesis: a report of four cases

Unilateral lung hypoplasia or agenesis can be asymptomatic or present with recurrent respiratory symptoms. The latter may be amenable to surgical treatment in selected cases. Of four children in this report, two are being managed without surgery. A third was relieved of his symptoms by pneumonectomy. The fourth presented with acute foreign-body inhalation into the healthy right main bronchus, and coexistent left pulmonary agenesis was discovered at bronchoscopy. Bronchoscopy and computed tomography were found to be the most useful investigations in management.

Effectiveness of case management with severely and persistently mentally ill people

This meta-analytic review synthesizes the findings of 24 published studies dealing with the effectiveness of case management with the severely and persistently mentally ill. Summative findings were: (1) Overall, case management interventions are effective--75% of the clients who participate in them do better than the average client who does not; (2) The estimated preventive fraction (e.g., prevention of re-hospitalization) among clients who experience relatively intense case management service (case loads of 15 or less, 89%) is nearly 30% greater than that estimated among similar clients receiving less intensive service; and (3) Various case management practice models did not differ significantly on estimated effectiveness. Important questions concerning the differential effectiveness of case management by specific program, worker, client, and client-worker relationship characteristics remain to be answered.

Achalasia cardia in infancy and childhood: an Indian experience

Seven children with achalasia cardia, six of them infants, were seen over a 10-year period. In infantile achalasia, respiratory symptoms predominate and vomiting may easily be mistaken for gastroesophageal reflux (GER). Vomiting of uncurdled milk is characteristic of achalasia. Six children underwent esophagocardiomyotomy with good results in five. The procedure was transthoracic in two and transabdominal combined with an anterior fundoplication in the others. There was one post-operative death. Achalasia and alacrima were associated in two infants. One baby with this association also had a neurogenic bladder.

Antenatal detection of hiatus hernia

A routine ultrasound scan in a primigravida at 29 weeks' gestation showed that her fetus had a fluid-filled viscus above the diaphragm in the mid-line. This was initially thought to be the stomach, either as part of a congenital Bochdalek diaphragmatic hernia or an hiatus hernia. Subsequent scans suggested that this was the stomach with an additional loop of bowel. After birth, laparotomy confirmed that the stomach had herniated into the chest through a very lax oesophageal hiatus. The stomach was easily reduced into the abdomen with no evidence to suggest a congenital short oesophagus, the crura were tightened, and an anterior fundoplication performed.

Two unusual cases of megacolons

A 13-year-old boy with features of intestinal obstruction was found at laparotomy to have a sigmoid volvulus. A 7-year-old girl with a similar presentation had a tight stricture at the rectosigmoid junction causing obstruction. In both cases the proximal colon was grossly loaded with faeces. In the first child, a colostomy after resecting the sigmoid colon was considered the safer option, whereas in the second, an innovative method to decompress the proximal loaded colon using a sterilised colostomy bag was employed, enabling a primary anastomosis to be performed.

Interaction of the fibrinolytic receptor, annexin II, with the endothelial cell surface. Essential role of endonexin repeat 2

Endothelial cells express a cell surface co-receptor for plasminogen and tissue plasminogen activator (t-PA) which we recently identified as annexin II (Hajjar, K. A., Jacovina, A. T., and Chacko, J. (1994) J. Biol. Chem. 269, 21191-21197). This protein enhances the catalytic efficiency of t-PA-dependent plasmin generation by 60-fold (Cesarman, G. M., Guevara, C. A., and Hajjar, K. A. (1994) J. Biol. Chem. 269, 21198-21203). Here, we demonstrate that annexin II is constitutively translocated to the endothelial cell surface within 16 h of biosynthesis, and that cell surface annexin II comprises 4.3 +/- 1.0% of the total cellular pool. Exogenous 125I-annexin II bound to EGTA-washed endothelial cells with high affinity (Kd 49 nM) and in a calcium-dependent (I50 = 3 microM), phospholipid-sensitive manner. Peptides KASMKGLGTDED and YDSMKGKGTRDK, mimicking the calcium-binding "endonexin" motif (KGXGT) of annexin II, blocked its interaction with endothelial cells. Recombinant annexin II, bearing the calcium-binding site substitution D161A of core repeat 2, failed to compete with binding of the wild type protein to the cell surface, while E246A and D321A mutants, corresponding to core repeats 3 and 4, behaved as effective competitors. These data suggest that translocated annexin II interacts with cell surface phospholipid via a high affinity calcium-dependent binding site that includes residues 118-122 (KGLGT) and the coordinating Asp161 of core repeat 2. Thus, calcium-regulated expression of annexin II on the endothelial cell surface may play a central role in control of plasmin-mediated processes.

Karyotypic evolution in a granulocytic sarcoma developing in a myeloproliferative disorder with a novel (3;4) translocation

A 59-year-old man presented with a granulocytic sarcoma arising in the manubrium, and splenomegaly. The blood count showed 1.2 x 10(9)/l eosinophils and a marrow aspirate was hypercellular with eosinophilia. Cytogenetic analysis of the marrow revealed a novel t(3;4) (p13;q12) and analysis of cells aspirated from the granulocytic sarcoma showed the same abnormality and an additional trisomy 8. Intensive chemotherapy and local radiotherapy led to resolution of the chest mass but persistence of the chromosome translocation in the marrow.

An endothelial cell receptor for plasminogen/tissue plasminogen activator. I. Identity with annexin II

Sequencing of two internal peptides from the putative human endothelial cell tissue plasminogen activator (t-PA) receptor identified an analog of the calcium- and phospholipid-binding protein, annexin II (Ann-II). The polymerase chain reaction-derived, full-length cDNA revealed complete sequence identity with the heavy chain of Ann-II, and ligand-precipitated receptor protein immunoreacted specifically with a monoclonal antibody to Ann-II. Transfected 293 cells bound plasminogen (Kd = 114 nM; Bmax = 347,000) as well as t-PA (Kd = 48 nM; Bmax = 380,000). Antisense oligonucleotides directed against endothelial cell Ann-II mRNA inhibited binding of both t-PA and plasminogen by 49% and 38%, respectively. The K307T mutant of Ann-II expressed on 293 cells failed to bind plasminogen, while the K328I mutant bound this ligand in a manner equivalent to the wild-type. Binding of plasminogen to both the wild-type and the K328I mutant was blocked by pretreatment of 293 cells with carboxypeptidase B. These data suggest a novel mechanism whereby a plasmin-like serine protease may cleave Ann-II at Lys307-Arg308, exposing a new carboxyl-terminal lysine residue (Lys307) for binding and efficient activation of plasminogen.

Intracardiac blood flow velocities and cardiac output in normal fetuses: a prospective pulsed Doppler echocardiographic study

Two dimensional and pulsed Doppler echocardiographic studies were performed in human fetuses with the aim to establish normal values for blood flow velocities and cardiac output in Indian subjects. Thirteen pregnant mothers were prospectively followed up at 4 weeks interval from 19 to 40 weeks of gestation. Blood flow velocity spectra across aortic, pulmonary, mitral and tricuspid valves were analyzed to obtain peak flow velocity (cm/sec) and velocity time integral. Aortic and pulmonary diameters were measured at the valve level from two dimensional echocardiographic images and ventricular stroke volume calculated. The values were plotted against fetal age (weeks) and fetal weight (gms). Our results showed that there is a linear increase of the measured Doppler data, with increasing gestational age and weight. These values may be used as a reference for the Indian population.

Mouse liver cell culture. I. Hepatocyte isolation

A method for isolation of mouse liver cells by a two-step perfusion with calcium and magnesium-free Hanks' salt solution followed by a medium containing collagenase is described. Several variations of the commonly used procedure for rat liver cell isolation were quantitatively compared with respect to cell yield and viability. The optimal isolation technique involved perfusion through the hepatic portal vein and routinely produced an average of 2.3 x 10(6) viable liver cells/g body weight. Optimal perfusate collagenase concentration was found to be 100 U of enzyme activity per milliliter of perfusate. Light and electron microscopic evaluation of liver morphology after several steps of the isolation showed distinct morphologic changes in hepatocytes and other liver cells during perfusion. After perfusion with Hanks' calcium- and magnesium-free solution, many hepatocytes exhibited early reversible cell injury. These changes included vesiculation and slight swelling of the endoplasmic reticulum as well as mitochondrial matrix condensation. Subsequent to perfusion with collagenase, the majority of hepatocytes appeared connected to one another only by tight junctional complexes at the bile canaliculi. Multiple evaginations were seen on the outer membrane resembling microville and probably represented the remains of cell-to-cell interdigitations between hepatocytes and sinusoidal lining cells from the space of Disse. The cytoplasmic injury seen after Hanks' perfusion was reversed after collagenase perfusion. After mechanical dispersion, isolated mouse hepatocytes were spherical in shape and existed as individual cells; many (80 to 85%) were binucleated under hase contrast light microscopy. By electron microscopy, cells appeared morphologically similar in cytoplasmic constitution to that seen in intact nonaltered liver cells.