The 100th anniversary of pH (1909-2009). Negative logarithms for measuring hydrogen ions: are they essential in medicine? Part I

Introduction: It has been 100 years since the concept of pH (1909-2009) was ‘‘invented’’ by the Danish chemist-mathematician Søren Peter Lauritz Sørensen (1868-1939) in the chemistry laboratories of the Carlsberg Brewery in Copenhagen. The anniversary provides an opportunity to examine the crucial importance in human life of acid-base balance. Materials and methods: The authors review the historical process that led to the creation of the pH scale, with citation of passages from the original work of Sørensen published 100 years ago. This is followed by a critical analysis of the debate regarding the use of logarithmstomeasure hydrogen ion concentrations based on data from scientific papers published over the past 50 years (1960-2010). Results and discussion: The authors conclude that the concept of acid-base balance can be approached and taught in a simpler, more exciting, and even pleasant fashion without using the infamous and abstruse Henderson-Hasselbalch equation. The whole rationale underlying the understanding and clinical application of this vital topic is clearly and unquestionably inherent simpler, more manageable formula introduced by Henderson (without logs), which is useful and quite adequate for use in medical education.

The 100th anniversary of the invention of pH (1909-2009) - Part II. Was it really necessary to replace the Henderson equation with that of Henderson-Hasselbalch?

Introduction: The year 2009 marked the centenary of the ‘‘invention’’ of the concept of pH by the Danish chemist-mathematician Søren Peder Lauritz Sørensen (1868-1939), who was working at the time in the chemistry laboratories of the Carlsberg Brewery in Copenhagen. The occasion provides an opportunity to re-examine a concept that is crucial for the understanding of human life–—namely, acid-base balance. This article provides an overview of acid-base pathophysiology and the historical events that led from the simple equation of Henderson to the much more complex one developed by Hasselbalch. Conclusions: The authors conclude that the issue of acid-base balance would be easier to understand, more exciting, and even more pleasant if it were taught without recourse to the infamously abstruse Henderson-Hasselbalch equation. Unquestionably, the whole rationale underlying the understanding and clinical application of this vital concept is already inherent in the simpler, more manageable formula of Henderson (without logs), which is both useful and sufficient for use in medical school curricula.

Efficiency of liposomes in the delivery of a photosensitizer controlled by the stereochemistry of a gemini surfactant component

Liposomes formulated with dimyristoyl-sn-glycero-phosphatidylcholine, DMPC, and either one of the cationic gemini surfactants (S,S)-2,3-dimethoxy-1,4-bis(N-hexadecyl-N,N-dimethylammonio)butane bromide, 1a, and (S,R)-2,3-dimethoxy-1,4-bis(N-hexadecyl-N,N-dimethylammonio)butane bromide, 1b, were investigated as vehicles of the photosensitizer m-tetrahydroxyphenylchlorin, m-THPC, to cell models of malignant glioma. The delivery efficiency of DMPC/1a and DMPC/1b liposome formulations were evaluated on the murine glioblastoma cell line C6 and on the human glioblastoma cell line LN229 by flow cytometry and laser scanning confocal microscopy. The stereochemistry of the spacer of the gemini was found to strongly influence the delivery efficiency of m-THPC to cells, the mode of interaction with the cell membrane, and the intracellular distribution of m-THPC. The physicochemical features of liposomes were investigated with the aim of explaining the parameters that control their biological features. Differences that could account for the different biological activity of the formulations concern the values of surface potential and the environment of m-THPC at the water/liposome interface.

[Second-look in ovarian cancer: laparoscopy or laparotomy?]

BACKGROUND

The aim of the present study was to compare the laparoscopic second-look with laparotomic second-look as regards the consistency of diagnosis of residual tumoral disease after first step treatment in patients affected by ovarian cancer, and to evaluate the feasibility of the laparoscopic second-look.

METHODS

Twenty-one patients affected by ovarian cancer underwent laparoscopic second-look followed by laparotomic second-look. Six months after the first surgical intervention all the patients showed no contraindications to laparoscopic second-look. All the surgeries were performed with the same procedure: after the introduction of the trocars the lysis of adherences was carried out, the whole abdominal cavity was explored, 18 abdominal-pelvic sites were examined, direct biopsies were performed and samples for the cyto- and histological analysis were obtained.

RESULTS

Positive predictive value for laparoscopy was 100% (6 out of 6 cases), while negative predictive value was 84% (2 false negative cases out of 12). The complete abdominal-pelvic examination was possible in 95% of cases with laparotomy while in 41% of cases with laparoscopy, because of post-operative severe adherences.

CONCLUSIONS

Laparoscopic second-look has a good consistency as regards the diagnosis of residual tumoral disease, but its feasibility is lower than laparotomy owing to the presence of severe adherences and the high risk of intra- and post-operative compliances.

[Cytoreductive surgery in patients with stage IV ovarian carcinoma]

BACKGROUND

The aim of this study is to evaluate the efficacy of cytoriductive surgical in females with ovarian carcinoma in advanced stadium, and to define the role of this surgical for the survival of females with hepatic metastases.

METHODS

This is a retrospective study. 164 females with ovarian cancer in IV stadium was examined. 64 females had hepatic metastasis. All patients had cytoriductive surgical.

RESULTS

The survival in the patients without hepatic metastasis was 38 months if the cytoreduction was very good; it was 18.3 months if there is residual disease. The survival in the patients with hepatic metastasis was 50.1 months if the cytoreduction was very good; it was 27 months if there is residual disease.

CONCLUSIONS

A very good surgical is very important for the survival of patients with ovarian cancer in advanced stadium. This is true also in the patients with hepatic metastases.