Discovery of highly potent small molecule kallikrein inhibitors

Uncontrolled kallikrein activation is involved in diseases such as hereditary angioedema, bacterial septic shock and procedures such as cardiopulmonary bypass. Here we report a series of small molecule compounds that potently inhibit kallikrein activity in vitro. Kinetic studies indicate that some of these compounds are slow binding inhibitors of kallikrein with Ki final less than a nanomolar. The ability of these compounds to inhibit the activity of kallikrein was further confirmed in a plasma model by quantitating the release of bradykinin, an endogenous cleavage product of plasma kallikrein. To understand the inhibitory mechanism of the selected compounds toward kallikrein, the interactions between the selected compounds and kallikrein was explored using molecular modeling based on the information of crystal structures of TF/FVIIa and kallikrein. The information presented in the current study provides an initial approach to develop more selective and therapeutically useful small molecule inhibitors.

Effect of anti-Helicobacter pylori therapy on outcome of iron-deficiency anemia: a randomized, controlled study

BACKGROUND

Helicobacter pylori infection may play a role in iron-deficiency anemia.

METHODS

In 52 patients with iron-deficiency anemia, H. pylori status was determined using rapid urease test and histology. H. pylori -positive patients were randomly assigned to receive anti- H. pylori treatment either immediately (Group I) or after a delay of one month (Group II); in addition, all patients received oral ferrous sulfate for three months. Patients testing negative for H. pylori (Group III) received only oral ferrous sulfate. Hematological parameters were tested every month.

RESULTS

Of 52 patients, 32 (61.5%) had H. pylori infection. At the end of one month, median increase in hemoglobin level was lower in Group II than in Groups I and III (1.1 g/dL vs. 3.6 g/dL and 1.9 g/dL, respectively; p=0.025), as were that in serum iron (19 mcg/dL vs. 55.5 mcg/dL and 41 mcg/dL; p=0.019). During the second month, after H. pylori infection in Group II had been treated, median increase in hemoglobin in this group was comparable to those in Groups I and III (3.7 g/dL vs. 2.5 g/dL and 2.5 g/dL.

CONCLUSION

In patients with iron-deficiency anemia, presence of H. pylori infection is associated with a poorer response to oral iron therapy, which improves with treatment for H. pylori infection.

Evidence for a carbonyl-containing intermediate in the 308-nm photolysis of trans-RhCl(CO)(PMe3)2

Time-resolved infrared absorption spectroscopy is used to monitor the events during the first approximately 100 mus following 308-nm photolysis of trans-RhCl(CO)(PMe3)2 (I) in a C6D6 or Decalin solution. Upon photolysis, the intensity of the carbonyl stretching absorption of I decreases and a new C-O stretching absorption (A) appears at 2006 cm(-1) in C6D6 (2013 cm(-1) in Decalin). Within approximately 100 mus, A disappears concurrently with partial regeneration of I and oxidative addition of a solvent C-D (C-H) bond. Our observation of the prompt formation of a carbonyl-containing intermediate contrasts with prior observations that photolysis at longer wavelengths leads solely to dissociation of CO from I. The implications of the observation of A for the understanding of the mechanisms of photocatalytic reactions of I are discussed.

PUO due to Langerhans Cell Histiocytosis

Langerhan Cell Histiocytosis (LCH) is a disorder in which cells with a phenotype similar to that of epidermal langerhans cells cause tissue damage possibly through excessive cytokine production. The clinical spectrum of the disease is wide. We are reporting a case of LCH who presented with prolonged pyrexia and a clinically benign bony swelling of mandible of long duration, which was otherwise ignored as being unrelated. The biopsy from the swelling confirmed the diagnosis of LCH. Another biopsy from lower end of tibia where he had pain also demonstrated typical findings. There was no evidence of other system involvement. There was good remission of the swellings and the symptoms with steroid alone initially but later relapsed and is now on treatment as per LCH III protocol. The case is being reported for its rarity and for the unusual presentation as PUO.

Role of ultrasound in dengue fever

This study was performed to find out whether ultrasound is an important adjunct to clinical and laboratory profile in diagnosing dengue fever or dengue haemorrhagic fever and to further determine whether ultrasound is useful in predicting the severity of the disease. Ultrasound was performed on 128 patients (2-9 years) with clinical suspicion of dengue fever. Serological tests were performed to confirm the diagnosis. 40 patients were serologically negative for dengue fever and later excluded from the study. Of the remaining 88 serologically positive cases, 32 patients underwent ultrasound on second to third day, repeated on fifth to seventh day of fever and in 56 patients ultrasound was done only on fifth to seventh day of fever. Of the 32 patients who underwent the study on second to third day of fever, all showed gall bladder wall thickening and pericholecystic fluid, 21% had hepatomegaly, 6.25% had splenomegaly and right minimal pleural effusion. Follow-up ultrasound on fifth to seventh day revealed ascites in 53% left pleural effusion in 22% and pericardial effusion in 28%. Of the 56 patients who underwent the study on fifth to seventh day of fever for the first time all had gall bladder wall thickening, 21% had hepatomegaly, 7% had splenomegaly, 96% had ascites, 87.5% had right pleural effusion, 66% had left pleural effusion and 28.5% had pericardial fluid. To conclude, in an epidemic of dengue, ultrasound features of thickened gall bladder wall, pleural effusion and ascites should strongly favour the diagnosis of dengue fever.

Removal of the superficial zone of bovine articular cartilage does not increase its frictional coefficient

OBJECTIVE

To investigate the role of the superficial zone in regulating the frictional response of articular cartilage. This zone contains the superficial protein (SZP), a proteoglycan synthesized exclusively by superficial zone chondrocytes and implicated in reducing the friction coefficient of cartilage.

DESIGN

Unconfined compression creep tests with sliding of cartilage against glass in saline were carried out on fresh bovine cylindrical plugs (slashed circle Ø6 mm, n=35) obtained from 16 bovine shoulder joints (ages 1-3 months). In the first two experiments, friction tests were carried out before and after removal of the superficial zone ( approximately 100 microm), in a control and treatment group, using two different applied load magnitudes (4.4 N and 22.2 N). In the third experiment, friction tests were conducted on intact surfaces and the corresponding microtomed deep zone of the same specimen.

RESULTS

In all tests the friction coefficient exhibited a transient response, increasing from a minimum value (mu(min)) to a near-equilibrium final value (micro(eq)). No statistical change (P>0.5) was found in micro(min) before and after removal of the superficial zone in both experiments 1 and 2. However, micro(eq) was observed to decrease significantly (P<0.001) after removal of the surface zone. Results from the third experiment confirm that micro(eq) is even lower at the deep zone. Surface roughness measurements with atomic force microscopy (AFM) revealed an increase in surface roughness after microtoming. Immunohistochemical staining confirmed the presence of SZP in intact specimens and its removal in microtomed specimens.

CONCLUSIONS

The topmost ( approximately 100 microm) superficial zone of articular cartilage does not have special properties which enhances its frictional response.

Restrictive cardiomyopathy due to primary plasma cell leukemia

The causes of restrictive cardiomyopathy are numerous, of which neoplastic infiltration is also known. Plasma cell leukemia is considered as the, most severe form of multiple myeloma, is an extremely rare condition. Among them, primary plasma cell leukemia has got an incidence of one in one million only. We report a case summary of a patient who was admitted with clinical features suggestive of restrictive cardiomyopathy, the underlying disorder was primary plasma cell leukemia. With chemotherapy the restrictive physiology was relieved supporting the diagnosis of plasma cell infiltration in the myocardium. We report this case due to rarity of the disease itself and its rare presentation.

Robot-assisted navigated endoscopic ventriculostomy: implementation of a new technology and first clinical results

BACKGROUND

Important landmarks in the evolution of advanced neurosurgical techniques during the past decades include microneurosurgery, neuro-endoscopy and its minimally invasive nature, as well as neuronavigation and advanced intra-operative imaging. With conventional neuroendoscopic techniques, e.g. free-hand endoscopy or the use of mechanical or pneumatic holding devices, a definitive and controlled movement of the endoscope within the brain does depend on the experience and manual skill of the individual neurosurgeon. Therefore, the development of robotic systems to assist surgeons in performing complex neurosurgical procedures is a growing field of interest.

METHOD

With the precision robot "Evolution 1" (U.R.S. Universal Robot Systems, Schwerin, Germany) a new neurosurgical tool has just become available for the precise steering of instruments within the cranium. After preclinical anatomical as well as precision studies the system was used for robot-assisted navigated endoscopic third ventriculostomies in six patients with hydrocephalus related to aqueductal stenosis.

FINDINGS

All robot-assisted navigated endoscopic procedures were successfully completed. The time for the registration procedure and setup of the robot decreased from 60 min. for the first procedure down to 30 min. The time for the surgical part of the neuro-endoscopic procedure itself ranged from 17 to 35 min. During all procedures no system-related complications occurred.

INTERPRETATION

The use of robotic technology for neuro-endoscopic third ventriculostomies is a major step towards the controlled movement of the neuro-endoscope within the cranium. The start up procedure and calibration of the robot is still time consuming, but the real operation time is comparable to free hand neuro-endoscopy. The steering of the endoscope is facilitated and the precision of the endoscopic movements is noteworthy.

Comparison of the expression of beta-catenin in hepatocellular carcinoma in areas with high and low levels of exposure to aflatoxin B1

BACKGROUND AND OBJECTIVES

Previous studies showed that the frequency of beta-catenin mutation was different in mice when induced by different chemicals. The aim of this study is to compare the expression of beta-catenin and p53 in hepatocellular carcinoma (HCC) from areas with exposure to high and low levels of aflatoxin B1 (AFB1).

METHODS

Thirty-five and twenty HCC samples from Guangxi and Malaysia, respectively, were studied. The expression of beta-catenin and p53 was determined by immunohistochemistry.

RESULTS

The overexpression of beta-catenin was detected in 65.7% of HCC tissues and 37.1% in adjacent liver tissues samples from Guangxi, China. Similarly, overexpression of beta-catenin was also detected in 60.0% of HCC tissues and in 35.0% of adjacent liver tissues samples from Malaysia. The overexpression of p53 was detected in 42.9% of HCC specimens from Guangxi and in 25.0% of HCC specimens from Malaysia. There was a relationship between the expression of beta-catenin and hepatitis B virus (HBV) infection in the adjacent liver tissues in Guangxi, and between the expression of beta-catenin and p53 in HCC tissues in Malaysia.

CONCLUSIONS

The differences in the exposure to AFB1 did not affect the overexpression of beta-catenin in the development of HBV-associated HCC.

Complete axillary conversion after neoadjuvant chemotherapy in locally advanced breast cancer: a step towards conserving axilla?

OBJECTIVES

This study was designed to assess the clinical, sonographic and histopathological response of axillary lymph node metastasis to neoadjuvant chemotherapy in patients with locally advanced breast cancer.

MATERIAL AND METHODS

Forty patients with locally advanced breast cancer (LABC) with clinically palpable or sonographically detectable axillary nodes were studied. FNAC of the primary tumor and axillary nodes was done and patients were started on neoadjuvant chemotherapy. Axillary nodes were assessed clinically and sonographically for response after 3 cycles of chemotherapy. All patients underwent total mastectomy with axillary clearance and the lymph nodes in the specimen were examined for metastasis.

RESULTS

47% patients had complete clinical nodal response, while 19% showed complete sonographic response. Complete pathological nodal response was documented in 22% of patients. Ultrasonography was found to be more sensitive than clinical examination in assessing complete nodal response. 10% of the patients had complete pathological response of both primary tumor and axillary nodes. There was significant correlation between pathological response of primary tumor and lymph nodes (P=0.004). Patients with complete sonographic or clinical response were found to have no or minimal residual disease in axilla and hence axillary dissection may be avoided in them.

GSK-3beta phosphorylation and alteration of beta-catenin in hepatocellular carcinoma

The aim of this study is to investigate the potential correlation between the expression of phosphorylated glycogen synthase kinase-3beta (phospho-GSK-3beta) and beta-catenin, and the mutations of beta-catenin gene at the consensus GSK-3beta phosphorylation site. The reason for this approach is to gain a better understanding of the molecular mechanisms of hepatocarcinogenesis in Malaysia. The expression of phospho-GSK-3beta and beta-catenin by immunohistochemistry and the mutations of beta-catenin were studied in 23 hepatocellular carcinoma (HCC) and surrounding tissues. Overexpression of phospho-GSK-3beta and beta-catenin was found in 12/23 (52.2%) and 13/23 (56.5%) in HCC tissues, 6/23 (26.1%) and 9/23 (39.1%) in surrounding tissues, respectively. Overexpression of beta-catenin in HCC tissues compared to the surrounding liver tissue was found to be higher in HCC tissues (p=0.015). In addition, we found that the expression of phospho-GSK-3beta was related with the accumulation of beta-catenin in surrounding tissues (p<0.05). The expression of phospho-GSK-3beta and its association with the development of HCC is reported for the first time. In addition, this is the first report from Malaysia which shows that there are no mutations at the GSK-3beta consensus phosphorylation sites on beta-catenin gene in all 23 paired HCC and surrounding tissues. This result differed from HCC in geographical areas with high aflatoxin exposure.