A simple technique to reduce the incidence of accidental dural puncture

We would like to respond to recent comments (Reynolds. Anaesthesia 2001: 56 : 1129) on our epidural technique. In our practice we apply loss of resistance to air technique, which helps identify a nick in the dura with a small leak of CSF. On many occasions, only a few drops of CSF and not a constant leak helped identify dural puncture, which could have been missed with the use of saline. Upon inserting the epidural needle, we remove the stylet when the needle is engaged in the interspinous ligament or the ligamentum flavum. Very often, it is difficult for our residents to advance the epidural needle with one hand and apply constant pressure on the plunger with the other hand. Excessive pressure with one hand, by a resident, had caused dural puncture when the needle was pushed in too far. By reinserting the stylet with each advancement of the needle, we remove tissues that may enter and occlude the epidural needle. It is quite possible that constant plunger pressure with saline may also avert this problem.     

Microcellular polyHIPE polymer supports osteoblast growth and bone formation in vitro

A novel micro-cellular polymer with a well-defined and uniform micro-architecture has been developed as a three-dimensional support matrix for in vitro tissue engineering applications. This material is manufactured through a high internal phase emulsion (HIPE) polymerization route and may be modified with hydroxyapatite. The generic form of the support is known as PolyHIPE Polymer (PHP). By changing the chemical composition of the emulsion and the processing conditions, the pore size can be altered from sub-micron range to a few hundred microns and the porosity varied from 70% to 97%. Our work has investigated the use of this micro-porous polymer as a biomaterial to support the growth of osteoblasts, the bone forming cells in vitro. Three groups of polymers were used that had pore sizes of 40, 60 and 100 microm. Results demonstrated in vitro cell-polymer compatibility, with osteoblasts forming multicellular layers on the polymer surface and also migrating to a maximum depth of 1.4mm inside the scaffold after 35 days in culture. PHP was also able to support the differentiation of osteoblasts and the production of a bone-like matrix. The effect of modifying the polymer with hydroxyapatite was also studied and showed that there was a significant increase in osteoblast numbers penetrating into the polymer. There were few differences, between the pore sizes studied, on the overall penetration of osteoblasts into the polymer but the rate of movement into 100 microm PHP was significantly higher compared to the other sizes investigated. This study shows that osteoblasts seeded onto PHP demonstrate cellular attachment, proliferation and ingrowth leading to the support of an osteoblastic phenotype. Therefore this highly porous scaffold has a potential for bone tissue engineering.     

Analysis of menstrual, reproductive, and life-style factors for breast cancer risk in Turkish women

The aim of this study was to investigate the association between menstrual, reproductive, and life-style factors and breast cancer in Turkish women. In a hospital-based case-control study in Ankara, 622 patients with histologically confirmed breast cancer were compared with 622 age-matched controls, admitted to the same hospital for acute and non-neoplastic diseases. Unconditional logistic regression was used to estimate odds ratios (ORs) and 95% confidence intervals (CI) related to risk factors. Overall, menopausal status and age at menopause were found to be significantly associated with breast cancer. Having a full-term pregnancy and early age at first birth were associated with decreased breast cancer risk (OR=0.45, 95% CI=0.30–0.66; OR=0.34, 95% CI=0.22–0.53, respectively). Postmenopausal women with lactation longer than 48 mo had reduced risk of breast cancer (OR=0.36, 95% CI=0.14–0.93). In conclusion, decreased parity, late age at first birth, early menopause, and shorter duration of lactation were the most important determinants of breast cancer risk in Turkish women.     

Optimal control of a parabolic distributed parameter system via orthogonal polynomials

A class of optimal control of systems with distributed parameters is considered. The process of the systems under consideration is governed by a linear parabolic partial differential equation. By use of the modal space technique, the optimal control of a distributed parameter system is simplified into the optimal control of a linear time-invariant lumped-parameter system. Next, a direct computational method for evaluating the modal optimal control and trajectory of the linear time-invariant lumped-parameter is suggested. The method is based on using finite interpolating orthogonal polynomials to approximate modal state variables. The formulation is straightforward and convenient for digital computation. An illustrative example is given to demonstrate the advantage of this method. © 1998 John Wiley & Sons, Ltd.     

Hepatitis B and measles seroprevalence among Turkish children

This study was performed to determine hepatitis B and measles seroprevalence among the population under 30 years of age in Turkey. Blood samples of 2,683 subjects from eight provinces of Turkey were studied. Measles IgG was determined by hemagglutinin inhibition method, and hepatitits B surface antigen (HBsAg), anti-hepatitis B surface antibody (anti-HBs) and anti-hepatitis B core antibodies (anti-HBc) were determined by ELISA method. Overall seropositivity for measles was found to be 59.6%. There was a significant difference in seropositivity among provinces. The seropositivity was found to increase with age. The overall seropositivities for HBsAg, anti-HBs and anti-HBc were found to be 5.4%, 17% and 15.1%, respectively. The seroprevalences differed significantly among provinces. Although seroprevalence for anti-HBs and anti-HBc increased with age, HBsAg seropositivity did not change significantly after one year of age. Seroprevalence was not affected by sex. It was concluded that every effort should be given to vaccinate infants as early as possible for hepatitis B and that the coverage of infancy measles vaccination should be increased with a second dose.     

A rare post-transplant malignancy, cerebellar hemangioblastoma: a case report

INTRODUCTION: Post-transplant malignancies are among the most important complications in organ transplantation. Hemangioblastoma (HB) is especially prevalent in the cerebellum. CASE REPORT: A 20-year-old male who first started dialysis therapy, and then underwent kidney transplantation from a living-relative donor. Five years after transplantation, the patient suffered from vertigo and imbalance when walking. On cranial magnetic resonance imaging (MRI), a mass lesion in the right cerebellar hemisphere was observed, 3 x 3 x 3 cm in size, which was pushing against the fourth ventricle, and the right cerebellar peduncle. The patient had significant hydrocephaly. The mass lesion was removed by craniectomy. The pathological diagnosis was cerebellar hemangioblastoma. The symptoms and clinical findings improved. The patient was diagnosed with sporadic hemangioblastoma. Rapamycin therapy was started instead of cyclosporine, and the patient is being followed up without further problems. DISCUSSION: HB causes 2% of all intracranial tumors in the general population. It is generally sporadic in nature and approximately 20% can be associated with von Hippel-Lindau (VHL) syndrome. As in this case, MRI is preferred for the diagnosis. There was no pathology related to VHL disease in this patient's physical examination, family history, routine biochemical tests and abdominal MRI. The treatment is surgical excision of the tumor, as in this case. CONCLUSION: When cerebellar symptoms occur or a cerebellar mass lesion is detected in an organ recipient, HB should be considered in the differential diagnosis. The examination of patients with HB for a possible association with VHL disease is also required.     

Diamminodichloroplatinum combination chemotherapy in non-oat cell carcinoma of the lung

A comparison is made between four different but similar approaches to the chemotherapy of 250 patients with nonoat cell bronchogenic carcinoma of the lung. Combination chemotherapy, particularly in regimen where platinum is included, provided no significant advantages over single agent chemotherapy. Side effects attributed to platinum tend to distract from any modest therapeutic gains achieved through its use. Responses rates were not significantly increased through use of platinum in the chemotherapy combination reported in this study.     

Developing a surveillance system for HIV/AIDS in Pakistan

Apart from other interventions, surveillance remains a major focus of the national response to HIV/AIDS. However, with a shift in the epidemic pattern, the existing surveillance strategies are barely insufficient and long-term structural changes are desirable. This article provides a conceptual framework for developing a scientific system for HIV surveillance in Pakistan. Second generation surveillance system including repeated cross-sectional surveys in high risk population groups are suggested to collect behavioral and serological data at regular intervals on an annual basis to monitor the epidemic trend as well as the associated behaviors. In addition, multiple data resources have been highlighted, which could be coordinated to describe the epidemic pattern in the country. This information should form the basis for national prevention planning and ought to be used for making sensible choices through which prevention efforts are most likely to reduce new infections.