The effect of TGF-beta delivered through a collagen scaffold on wound healing

In this preliminary study, the wound healing response of full-thickness skin defects to transforming growth factor beta (TGF-beta) incorporated in a collagen scaffold was evaluated. The objectives of this study were (1) to compare the effects of TGF-beta on the cellular and tissue response and mechanical properties and (2) to determine the effects of a collagen scaffold on wound healing when compared to control. Three 3 x 3 cm, full-thickness defects were created on the dorsi of 15 New Zealand White rabbits. Each rabbit had a control (no treatment), collagen scaffold, and collagen scaffold with TGF-beta (2 microg/cm2). All the wounds were covered with a transparent polyurethane dressing. There were three periods of study (1, 2, and 3 weeks) with five rabbits in each period. The volume fraction of the tissue and cells was histomorphometrically determined for each wound. A greater inflammatory response was found in the collagen scaffold-treated group, but the fastest epithelialization and contraction rates were associated with TGF-beta and collagen. No significant differences in the mechanical strength between the different treatment groups were seen. Overall, TGF-beta delivered through a collagen scaffold enhanced the healing process and showed promise for future clinical applications.

B7 costimulation is required for IL-5 and IL-13 secretion by bronchial biopsy tissue of atopic asthmatic subjects in response to allergen stimulation

Asthma is a complex disorder characterized by airway hyperreactivity and inflammation. To analyze cellular interactions required for the secretion of cytokines by the bronchial mucosa, we have evaluated the ex vivo response of tissue explants to allergen. Endobronchial mucosal biopsy tissue from mild atopic asthmatic subjects and normal control subjects were maintained in culture for 24 h. To detect reactivity to allergen, the explants were stimulated with dust mite extract Dermatophagoides pteronyssinus (Der p). Our analysis revealed that without any overt stimulation, mRNA transcripts for interleukin (IL)-5 and IL-13 were expressed by asthmatic but not normal bronchial tissue. In contrast, the expression of interferon-gamma was observed in a higher proportion of cultured bronchial biopsies from the normal control subjects than in those from asthmatic subjects. Addition of Der p allergen did not change the cytokine profile of the explants from control volunteers but augmented the expression of IL-5 mRNA and induced secretion of the protein by the asthmatic bronchial tissue. In most cases, allergen also increased the production of IL-13 by bronchial tissue from asthmatic subjects. The allergen-induced secretion of IL-5 and IL-13 was inhibited by the fusion protein CTLA-4Ig, reflecting a requirement for CD80 (B7-1) and/or CD86 (B7-2) costimulation for the expression of the Th2 cytokines. This requirement for B7/CD28 costimulation is consistent with the hypothesis that IL-5 and IL-13 are produced by allergen-specific T cells resident in the asthmatic bronchial mucosa.

Evaluation of trickle bed air biofilter performance as a function of inlet VOC concentration and loading, and biomass control

The 1990 Amendments to the Clear Air Act have stimulated strong interest in the use of biofiltration for the economical, engineered control of volatile organic compounds (VOCs) in effluent air streams. Trickle bed air biofilters (TBABs) are especially applicable for treating VOCs at high loadings. For long-term stable operation of highly loaded TBABs, removal of excess accumulated biomass is essential. Our previous research demonstrated that suitable biomass control for TBABs was achievable by periodic backwashing of the biofilter medium. Backwashing was performed by fluidizing the pelletized biological attachment medium with warm water to about a 40% bed expansion. This paper presents an evaluation of the impact of backwashing on the performance of four such TBABs highly loaded with toluene. The inlet VOC concentrations studied were 250 and 500 ppmv toluene, and the loadings were 4.1 and 6.2 kg COD/m3 day (55 and 83 g toluene/m3 hr). Loading is defined as kg of chemical oxygen demand per cubic meter of medium per day. Performance deterioration at the higher loading was apparently due to a reduction of the specific surface of the attached biofilm resulting from the accumulation of excess biomass. For a toluene loading of 4.1 kg COD/m3 day, it was demonstrated that the long-term performance of biofilters with either inlet concentration could be maintained at over 99.9% VOC removal by employing a backwashing strategy consisting of a frequency of every other day and a duration of 1 hr.

Clinical predictors of outcome in hypoxic ischaemic encephalopathy in term neonates

Thirty-eight full-term infants with hypoxic ischaemic encephalopathy were followed up prospectively to determine simple predictors of outcome at 1 year. Three predictors of outcome, based on clinical examination alone, were evaluated. These were presence of seizures, grading of encephalopathy and neurobehavioural assessment at discharge from the hospital. Development was assessed using the Bayley scales of infant development, and a mental and motor quotient below 85 was considered to be delayed development. At 1 year, 15 infants showed delayed development; five of them had cerebral palsy. Predictive values were determined for each indicator. Seizures per se did not affect the outcome. All infants with mild encephalopathy were normal. The predictive value of moderate-to-severe encephalopathy was 50%. Abnormal neurobehaviour at the age of 7 days or at discharge, if earlier, was found to be the best predictor of outcome with a predictive value of 91.6%.

Acute thyrotoxic neuropathy--Basedow's paraplegia revisited

A forty seven year old woman with previously undetected goitre, developed thyroid storm in the immediate postoperative period. Forty eight hours after undergoing nephrolithotomy for renal calculus, she was noted to have flaccid areflexic quadriparesis, most marked in the lower limbs. Electrophysiologic studies revealed evidence of an asymmetric, mixed axonal and demyelinating, motor-sensory peripheral neuropathy. Ultrastructure of the sural nerve showed predominant abnormalities in the mitochondria and cytoskeletal elements compatible with thyrotoxicosis. Treatment of thyrotoxicosis coincided with recovery of symptoms. We believe that thyrotoxicosis precipitated an acute polyneuropathy the ultrastructure of which is being described for the first time.

Investigation of acidic fibroblast growth factor delivered through a collagen scaffold for the treatment of full-thickness skin defects in a rabbit model

In this study the wound healing response of full-thickness skin defects was enhanced through the use of acidic fibroblast growth factor using a collagen scaffold. The objectives of this study were (1) to compare the facilitatory effects of acidic fibroblast growth factor on the cellular response (fibroblast, neutrophil, macrophage, epithelial), tissue response (angiogenesis, collagen) and mechanical properties in a healing wound; and (2) to determine the effect of a collagen scaffold on wound healing when compared with the control. Three 3 x 3 cm full-thickness defects were created on the dorsi of 15 New Zealand White rabbits. Each rabbit had a control (no treatment), collagen scaffold, and collagen scaffold with FGF-1 (100 microg/cm2). All the wounds were covered with a transparent polyurethane dressing. There were three periods of study (1, 2, and 3 weeks) with five rabbits in each period. The volume fraction of the tissue and cells was histomorphometrically determined for each wound. The acidic fibroblast growth factor/collagen system showed promise in enhancing the healing process. Acidic fibroblast growth factor/collagen treatment increased angiogenesis, enhanced epithelialization, and reduced contraction rate over the control. A higher inflammatory response was indicated in the collagen scaffold treated group. Hence acidic fibroblast growth factor delivered through a collagen scaffold shows promise in future clinical applications.

Growth and development of twins compared with singletons at ages one and four years

OBJECTIVE

To compare the growth and development of twins with normal control singletons and also with matched 'high risk' singletons, at one and four years of age.

DESIGN

A four year prospective follow up study.

SETTING

High risk clinic (HRC) of a referral hospital.

SUBJECTS

Twin pairs enrolled in the HRC; normal full term singleton controls; and high risk "matched" singletons enrolled in the HRC.

METHODS

The height, weight and head circumference was measured at one and four years. Development was assessed at 1 year using the Bayley Scales of Infant Development. At 4 years, the intelligence quotient was determined by the Stanford Binet Intelligence Scale.

RESULTS

Forty two twins and an equal number of controls were assessed at one year. All the twins weighed less than 2 kg at birth. They lagged behind in all three parameters of growth, namely, height, weight and head circumference. AT 4 years, 24 twins came for follow up. Although, they had caught up for head circumference, they lagged behind in height and weight, particularly the group of fourteen SGA twins. The growth parameters of LBW twins and LBW matched singletons did not show any significant difference. At one year, the development of twins was within normal limits although the motor quotients were significantly lower than that of controls. At 4 years, the intelligence quotients of twins were well within normal limits.

CONCLUSIONS

Twins were lighter and shorter than controls at four years, particularly the SGA twins. The growth parameters of LBW twins and LBW matched singletons showed no significant difference. The intelligence of twins was normal at four years.

Haemophilus influenzae type b vaccine in India: need and timing, immunogenecity and tolerance

OBJECTIVE

(i) To assess the natural immunity and susceptibility to Haemophilus influenzae type b (Hib) infections in children in India. (ii) To study the immunogenecity and tolerance of Hib vaccine (ACTHIB) in young infants.

DESIGNS

(i) Cross sectional study. (ii) Prospective trial.

SETTING

Well baby and immunization clinics.

METHODS

(i) PRP antibody titers against Hib estimated in 172 healthy infants and children aged 1 month to 10 years. (ii) Antibody titres estimated before and after ACTHIB vaccine given with primary immunization (age group 6 to 8 weeks) in 50 babies.

RESULTS

(i) Naturally protective levels of Hib antibodies found in less than 20% of infants under one year, but in over 80% above 4 years. (ii) Seroconversion after ACTHIB vaccination was 100% with very high protective levels. There were no significant adverse reactions.

CONCLUSIONS

ACTHIB vaccine proved to be safe and highly immunogenic. As susceptibility to Hib is highest in the first year of life, the vaccine should be recommended in the primary immunization schedule (combined with DPT). The very high titers achieved suggest the possibility of decreasing the number of doses or the amount of antigen to reduce the prevalent high cost.

Pseudomyxoma peritoneii

A middle aged male patient presented with gradual distension of the abdomen. Imaging modalities showed classical features of pseudomyxoma peritoneii which was confirmed by aspiration cytology. Details of the case are described and relevant literature is reviewed.

Present interpretation of the role of copper in Indian childhood cirrhosis

A common killer disease of the past, Indian childhood cirrhosis (ICC), which became preventable and treatable in the early 1990s, is now rare. ICC must be clearly distinguished in Indian children from other chronic liver disorders including Wilson disease. Grossly increased hepatic, urinary, and serum copper concentrations are characteristic of ICC. These increased concentrations are easily demonstrated histologically with orcein-rhodanine staining. Environmental ingestion of copper appears to be the most plausible explanation for ICC, as shown by feeding histories, the prevention of ICC is siblings and in the Pune district by a change in feeding vessels, and the dramatic reduction in incidence of ICC throughout India. The nature and role of a second factor in the causation of ICC remains unclear, although an inherited defect in copper metabolism is strongly suspected. ICC, however, does not appear to be a straightforward early onset of Wilson disease because ceruloplasmin is consistently normal and clinical and histologic recovery is maintained in the long term despite withdrawal of D-penicillamine therapy. Descriptions of an ICC-like illness in the West suggest that different mechanisms (environmental, genetic, or both) can lead to the same end-stage liver disease: copper-associated childhood cirrhosis. ICC probably represents a specific form of copper-associated childhood cirrhosis that requires high environmental copper ingestion for its full expression.

A Demonstration of the Role of het Genes in Heterokaryon Formation in Neurospora under Simulated Field Conditions

An experimental system was developed for assessing the role of het genes in heterokaryon formation in Neurospora in nature. Burned sugar cane segments planted in soil were infected using a mixture of mutant ascospores of two genotypes. Neurospora ramified in the cane and erupted as distinct pustules of conidia. When ascospores carried identical het alleles, the (macro) conidial pustules which formed were heterokaryotic. On the other hand, when ascospores carried dissimilar het alleles, the pustules were homokaryotic. These results showed that stable heterokaryons between compatible strains can form in nature. When two strains are growing together on a natural substrate, heterozygosity at het loci serves to maintain their individuality.

Evaluation of immunogenicity and tolerance of single dose haemophilus influenzae type B (PRP-T) vaccine

OBJECTIVE

Evaluation of immunogenicity and acceptability of PRP-T vaccine among the Indian children.

DESIGN

Multicentric, open, parallel group, comparative study of Haemophilus influenzae type B vaccine, given as single (Group I) or associated (Group II) with DPT vaccine.

SETTING

Five different vaccination clinics.

SUBJECTS

125 children between the age group of 18-24 months.

PARAMETERS

Measurement of (i) pre and post vaccination antibody titres of Haemophilus influenze type B specific antibody; (ii) Adverse events; and (iii) Tolerance as graded by the physician.

RESULTS

Prevaccination antibody levels were > 0.15 mcg/ml in 56.3% in Group I and 35.7% in Group II. Post-seroconversion was seen in 97% in Group II receiving single and all in Group II (P > 0.05). The vaccine was well tolerated.

CONCLUSIONS

The probability of subclinical infection or cross immunity is high in India. ACTHIB vaccine has a good immunogenicity and tolerance and association with DPT does not modify the immunogenicity of ACTHIB vaccine.

Parenteral nutrition in the management of severe protracted diarrhea

Seventeen children aged 3 weeks to 19 months with severe Protracted Diarrhea (PD), and who were deteriorating on our standard management protocol (including special diets) were given Parenteral Nutrition (PN) for 4 to 19 days with crystalline aminoacid solution (Vamin N) in 10% dextrose and lipid emulsion (Intralipid 10%). Peripheral lines were used in majority (84%). Enteral feeds were started early and rebuilt as per tolerance. The mean daily protein and caloric intake achieved by hyperalimentation was 2.2 +/- 0.7 g/kg and 106 +/- 41 K cal/kg respectively. Diarrheal control and improvement in nutritional status was achieved in all but 4 who died (2 of refractory diarrhea and 2 of sepsis, 1 of which was probably PN related). Other PN related, treatable complications included thrombophlebitis (11.8%), sepsis (17.6%), and metabolic imbalance (17.6%). PN solutions and accessories alone cost an approximate average of Rs. 280/day, with extras for biochemical monitoring (Rs. 70/day) and special nursing (Rs. 200/day). Only 5 of the 13 survivors had a significant relapse of PD, within 5 to 80 days of discharge, necessitating further PN in 2. There were no further deaths. PN was therefore, found to be of life saving value in 13 of 17 children with severe protracted diarrhea and therefore, must be available in specialised units caring for such children.

Analysis of 105 uninodular goitres

Data on 105 solitary thyroid nodules, confirmed at surgery to be solitary, is presented. Six (5.7%) were malignant, 4 papillary and 2 follicular. The sensitivity and the specificity of 131I radionuclide thyroid scan (n = 90) were 100% and 24% respectively. Similarly, the sensitivity and specificity of fine needle aspiration cytology (n = 65) was 75% and 100% respectively. In both instances, the "gold standard" was the histopathology of the surgically removed nodule. In order to avoid unnecessary surgery, without missing malignancy, we would recommend the combination of radionuclide thyroid scan and FNAC for investigation of solitary thyroid nodules.

An unusual cause of bilateral diaphragmatic paralysis

In a patient who had a sudden onset of bilateral diaphragmatic paralysis after forceful neck manipulation complete, though gradual, recovery in lung function and transdiaphragmatic pressures was seen over three years. This is a previously unrecognised risk of neck osteopathy.

Ciprofloxacin in typhoid fever

The study covers 78 children with typhoid fever who were hospitalized in April & May 1990. Serious complications were present in 32% (toxemia 22%, ileus 25% and myocarditis 8%). Blood cultures were positive in 30 of 49 tested. Others were diagnosed by positive Widal test. In vitro cultures of S. typhi were resistant to chloramphenicol (90%), ampicillin (93%) and co-trimoxazole (97%). However all were highly sensitive to ciprofloxacin and moderately sensitive to cephalexin and gentamycin. Ciprofloxacin alone or in combination was given in 73 of the 78 children and found to be remarkably effective in controlling the disease and preventing relapse. No serious side effects were noted. The cohort is being followed up for possible long term adverse effects.