Cryopreservation of Rh negative blood for improved storage & utilisation by means of indigenous freezing bags & solutions & manual deglycerolisation

BACKGROUND & OBJECTIVES

Cryopreservation allows donor blood to be stored for years, rather than weeks as in liquid storage. This is an established procedure in countries with a developed blood transfusion service. Cryopreservation has not been introduced in India, possibly because of the presumed high cost and complexity of the procedure. An attempt is made in this study, to cryopreserve Rh negative blood in a mechanical freezer using indigenous bags and solutions and manual deglycerolisation to reduce the cost of preservation.

METHODS

RBCs to be frozen were weighed and transferred by sterile welding to an 800 ml freezing bag. Based on RBC weight, 400-500 ml of glycerol (5.7 MpH 6.8) was added as cryopreservative. After extracellular and intracellular equilibration, excess glycerol was removed by centrifugation. Glycerolised RBCs were frozen at -80 degrees C in a mechanical freezer. Cryopreserved units were thawed at 37 degrees C and deglycerolised. Twenty one patients were transfused with the frozen deglycerolised RBCs after the usual pre-transfusion tests.

RESULTS

Haematocrit (Hct) values of the frozen deglycerolised units, complied with required standards, before addition of glycerol and post glycerolisation. RBC recovery was more than 80 per cent and Hct 83.3 per cent after deglycerolisation. Twenty one patients transfused with the frozen deglycerolised blood experienced no adverse effects and showed a 24 h mean post transfusion Hb increment of 0.73 g/dl.

INTERPRETATION & CONCLUSION

Cryopreservation, unlike liquid storage, allows Rh negative blood of the required ABO groups to be stocked. Cryopreservation also improves its utilisation, reduces wastage and helps supplement the liquid stocks of Rh negative blood. The use of indigenous freezing bags and manual deglycerolisation has resulted in an inexpensive procedure, which can be integrated, with minor inputs, into any blood bank that is already preparing blood components.

Teenage pregnancies in the Rewa medical sub-division, Fiji

To assess the magnitude of teenage pregnancies in the Rewa Medical Sub-division as well as the socio-demographic characteristics of the affected teenagers so as to provide a baseline for tackling the problem. The study was a 5 year retrospective study (1994-1998) of the medical records of the Nausori Maternity Unit, the only unit for these purposes in the entire Subdivision. Pregnancies that were intentionally terminated were not included, as no such data was available from these our public health services. An average of 11.1% of the 5319 obstetric patients attended to at the centre for the 5 years were teenagers. Their age range was 13 to 19 years. Proportionately more Fijians had such teenage pregnancies than their Indo-Fijian counterparts. The same was true of their being unmarried or being VDRL positive. A larger percentage of the Indian teenagers received assisted deliveries than the Fijians, but this was not statistically significant, being 6% and 4% respectively. Low birth weight was 19% among these teenagers (compared with 5.9% overall). Efforts are needed in the area of family life education to improve on aspects of teenage pregnancies. Since this is an area of education that has many conflicting values in the modern world, it is advocated that parents as well as many agencies as possible should be targets as well as join in this task in order meet the needs as due. Such education should cover and respect all the values concerned.

Management of ventricular septal defect: a survey of practice in the United Kingdom

BACKGROUND

A survey of pediatric cardiac surgeons was performed to establish current opinions in the United Kingdom concerning closure of ventricular septal defect.

METHODS

Questionnaires were sent to 14 pediatric cardiac centers in 1995 (16 surgeons, 100% response), and again in 1997 (20 surgeons, 100% response).

RESULTS

Results are presented for 1997, with findings from 1995 shown in parentheses. Eleven (6) surgeons used bypass exclusively, 9 (10) sometimes used circulatory arrest. Operative techniques were similar, although the material used for the patch varied. Multiple defects were approached via the transatrial route by 18 (15), right ventriculotomy by 11 (7) and left ventriculotomy by 7 (6). The juxta-arterial defect was approached via the transpulmonary route by 16 (13), a combination by 9 (11), transatrial by 10 (6), and transventricular by 9 (5). The most common indications for pulmonary arterial banding were "Swiss cheese" defect for 13 (13), and functionally single ventricle for 5 (6). Ventricular septal defect associated with coarctation was repaired in two stages by 13 (10), a single stage by 5 (3), or either by 1 (3).

CONCLUSIONS

Pediatric cardiac surgeons in the United Kingdom demonstrate a uniform, evidence-based approach to the management of ventricular septal defect.

Near-field probing of nanoscale nonlinear optical processes

We report a study of two nonlinear optical processes at the nanoscale level, using a near-field probe: (i) two-photon-pumped upconversion from ZnS:Mn nanoparticles encapsulated with 2-[{(?) -2-[4 -(ethylsulfonyl) phenyl]- 1-ethenyl} (methyl)anilino]- 1-ethanethiol and (ii) second-harmonic generation (SHG) from N -(4-nitrophenyl)- (L) -prolinol crystallites. The use of highly efficient nonlinear organic chromophores together with special processing on the nanometer scale made it possible to observe and characterize what are believed to be the smallest topographically distinguishable objects reported so far, using nonlinear optical techniques. Issues pertaining to the study of two-photon-excited emission and SHG by use of a near-field probe are discussed.

Reappearance of Vibrio cholerae O139 during March-August, 1998 in Ludhiana (Punjab), India

An outbreak of V. cholerae O139 was reported from Ludhiana in 1993. Strict bacteriological vigilance between 1994 and 1997 showed no isolates of O139, while 01 strains continued to be isolated. In 1998, 30 strains of V. cholerae O139 and 15 strains of V. cholerae 01 were isolated. Both strains appear to be endemic in Punjab.

Typing and antibiotic susceptibility patterns of Vibrio cholerae during six consecutive cholera seasons in north India

A total of 10,427 diarrhoeal stool specimens were cultured for Vibrio cholerae between 1992 and 1997. The isolation rates were 2%, 2.6%, 6.7%, 7.08%, 0.9% and 2.6% in the years from 1992 to 1997 respectively. Till 1992, Vibrio cholerae 01 ogawa was the predominant strain. In 1993, 81.3% of the isolates were of 0139 Bengal strain and the rest were V. cholerae 01. From 1994 to 1997, V. cholerae 01 ogawa was the predominant strain and there were no isolation of 0139 strain. The predominant phage type in 1992 and 1993 were T2 and T27 thereafter. Most Vibrio cholerae strains were sensitive to tetracycline, gentamycin, netromycin, norfloxacin and furazolidine. Strains were resistant to cotrimaxozole till 1996, but were 100% sensitive in 1997. Strains were sensitive to chloramphenicol till 1993 but acquired resistance thereafter.

Is there such a thing as the "tendon of the infundibulum" in the heart?

The fibrous skeleton of the heart has featured prominently in anatomical and surgical descriptions, although all its purported components are difficult to demonstrate. In descriptions of the skeleton, there have been repeated references to the presence of a tendon (or ligament) between the aortic and pulmonary roots. Such a tendon is rarely, if ever, discussed in the context of surgical procedures being carried out on the ventricular outflow tracts. Our study was undertaken, therefore, to investigate the existence and nature of such a tendon or ligament. Serial transverse sections were made through roots of aorta and pulmonary trunk in an intact fetal heart. In addition, ten normal adult hearts were dissected to display the components of the fibrous skeleton of the heart. No discrete fibrous or elastic structure could be detected in the tissue plane between the aortic sinuses and the subpulmonary muscular infundibulum, although a fascial strand was observed in one heart. Apart from this specimen, the space between the free-standing muscular subpulmonary infundibulum and the sinuses of aorta hearing the coronary arteries was occupied only by loose fibroareolar tissue. The initial presence of the ligament was described following studies of animal and macerated human hearts. Subsequently, it would seem its existence has been passed down through generations of morphologists and surgeons without its presence being reconfirmed. We have been unable to demonstrate any structure approximating to the initial illustrations.

Anatomy of the aortic root with particular emphasis on options for its surgical enlargement

BACKGROUND AND AIMS OF THE STUDY

The aortic root is a frequent site of surgical intervention, both in adults and children, yet there is ambiguity about the precise nature and relation of the various structures composing the aortic root. The present review aims to clarify these ambiguities and to explain the morphological basis of surgical procedures for enlargement of the aortic root.

MATERIALS AND METHODS

Using autopsied specimens of normal hearts, the morphology of the attachment of the leaflets, the interleaflet triangles and the circular ventriculo-arterial junction of the aortic root were studied in detail, paying special regard to fibrous and muscular continuity, relation to the atrioventricular conduction axis, and the coronary arterial branching. Surgical dissections and incisions required for enlargement of the aortic root were simulated in these specimens.

RESULTS

It was evident that the locus of attachment of aortic valvar leaflets takes the form of three (semilunar) crescents. This attachment is not circular, as the word 'annulus' suggests, neither does it correspond to the anatomical ventriculo-arterial junction. During implantation of a mechanical valve in the aortic position, a circular prosthetic valve ring is sutured on to the attachments of the native valvar leaflets. This must entail some distortion when the sutures are tied. Analysis of autopsied specimens showed that, on completion of the process of suturing, the location of the prosthetic valve is close to the anatomic ventriculo-arterial junction-one of the true annular regions of the aortic root.

CONCLUSIONS

The continuity of the aortic valvar leaflets and the interleaflet triangles with structures such as the aortic (anterior) leaflet of the mitral valve posteriorly, and with the muscular ventricular septum anteriorly, provide an opportunity for surgeons to enlarge the aortic root by widening of the anatomic ventriculo-arterial junction.

Prevalence of multi-drug resistant Salmonella typhi in Ludhiana Punjab

A total of 945 strains of S. typhi isolated from blood cultures during 1989 to 1994 were studied. Their antibiotic susceptibility showed 580 (61.4%) of strains to be multidrug resistant. The 464 strains tested for their susceptibility to ciprofloxacin were all sensitive to the drug. Twenty three (17.9%) of the 128 strains of S. paratyphi A were resistant to chloramphenicol. The sole isolate of S. paratyphi B was sensitive to all antibiotics tested.

Management of urinary calculi associated with renal failure

Three hundred and sixty patients of urinary calculi associated with renal failure were included in this prospective study. The male to female ratio was 4.1:1 while adult to paediatric ratio was 6.5:1. One hundred and eighteen (32.8%) patients presented with calculus anuria while 242 (67.2%) were admitted with symptoms of chronic renal failure. Serum creatinine at the time of first admission ranged from 3-35 mg/100 ml. In the initial management, percutaneous needle nephrostomy was done in 217 cases, dialysis in 106, dialysis and PCN in 22 and retrograde catheterisation followed by JJ stent in 15. Definitive surgical procedures were undertaken in 277 cases; 29 passed stones spontaneously after PCN. At two year follow-up 72% patients of calculus anuria and 49.5% of calculus renal failure improved their renal function and remained with serum creatinine below 2 mg/100 ml. There was 13.6% mortality in calculus anuria group and 17.4% in calculus renal failure. Overall loss to follow-up was 7.6% and 12% in the two groups respectively.

Outbreak of gastroenteritis due to a new strain of non O group 1 Vibrio cholerae, in Ludhiana in May-August 1993

The isolation of the new serotype 0139 of non 01 V. cholerae from an outbreak of gastroenteritis is reported. The study of 35 such isolates revealed their similarity with the El tor vibrios biochemically and by other characters. All were strongly haemolytic and 97.1 per cent of the strains showed a positive haemagglutination.