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Biomedical subjects

M Subrahmanyam

Publications and source records attributed to M Subrahmanyam.

At least 19 recordsLinked to original sources
PubMed2006

Hydroxyapatite-supported Ag-TiO2 as Escherichia coli disinfection photocatalyst.

A series of hydroxyapatite (HAP), 1wt% Ag-TiO(2) (AT1), 1wt% Ag-HAP and 5wt% AT1/HAP composite catalysts were prepared by incipient wetness and mechanical mixing methods. They were characterized by X-ray diffraction (XRD), FT-IR, SEM and ESCA analyses and their photocatalytic bactericidal activities were measured in suspension using Escherichia coli (E. coli), a water pollutant indicator. The surface analysis revealed that the Ag/Ti ratio is found to be ca. 0.0273 and also it indicated that the titania is present in the form of Ti(4+) and Ag is present as metallic silver. Both the XRD and ESCA analyses confirmed the phase of metallic Ag particles, which played a significant role on the bactericidal activity of the Ag doped TiO(2) catalysts. The FT-IR analysis of HAP revealed that the peak intensity is due to the absorbance of surface PO(4)(3-) group centered at wave number 1030cm(-1) and is drastically decreased upon exposure to UV for 1h. The HAP displayed high amount of bacteria adsorption, ca. 80% during the dark experiments compared to other catalytic systems tested. The cumulative photocatalytic properties of AT1/HAP catalytic system resulted in 100% E. coli bacteria reduction within 2min.

Adsorption↗
PubMed2003

Photocatalytic transformation of dyes and by-products in the presence of hydrogen peroxide.

The efficiency of the photocatalytic degradation of dyes and dyeing industry pollutants on immobilized photocatalysts can be improved by addition of hydrogen peroxide, due to its photocatalytic decomposition on TiO2. Experiments were carried out with two azodyes, Acid Orange-7 (AO-7) and Tartrazine (Tart), with 3-nitrobenzenesulfonic add (3-NBSA) which is a chemical intermediate in the dye industry and with real industrial wastewaters, using a thin-film fixed bed reactor. The effect of hydrogen peroxide is only significant for concentrations higher than 5 x 10(-3) M (170 mg l(-1)).

Bioreactors↗
PubMed1999

Early tangential excision and skin grafting of moderate burns is superior to honey dressing: a prospective randomised trial.

METHODS: In this prospective trial, 50 burn patients were randomised to be treated either with early tangential excision and skin grafting or by the application of honey dressings, with delayed skin grafting as necessary. The 25 patients in the tangential excision (TE) group had burns of 23 +/- 4%, 12% of which was full thickness. The honey treated patients (HT), (N=25), had burns of 24 + 4%, 13% of which was full thickness. Seventeen of the TE patients were operated upon on day 3, the remainder before day 6 post burn. Eleven of the HT patients eventually required skin grafting. Cosmetic and functional results were assessed at 3 months post discharge. RESULTS: In the TE group, the skin grafting take rate was 99 +/- 3%. In the HT group, the graft take rate was 74 +/- 18% (P < 0.01). The mean percentage of blood volume replaced was 35 +/- 12% in TE patients vs. 21 +/- 15% in HT patients (P < 0.01). Only one TE patient died due to status asthmaticus, while there were 3 deaths, all from sepsis, in the HT patients. At 3 month follow-up, 92% of the TE patients had good to excellent functional and cosmetic results vs. 55% in HT patients, 3 of whom had significant contractures. CONCLUSION: Early tangential excision and skin grafting was clearly superior to expectant treatment using topical honey in patients with moderate burns in this randomised, prospective study performed at a General Hospital in the Indian subcontinent. The availability of suitable allogenic blood is a potential problem when TE is employed.

Adolescent↗
PubMed1998

A prospective randomised clinical and histological study of superficial burn wound healing with honey and silver sulfadiazine.

Histological and clinical studies of wound healing have been made on comparable fresh partial thickness burns with honey dressing or silver sulfadiazine (SSD) in two groups of 25 randomly allocated patients. Of the wounds treated with honey 84 per cent showed satisfactory epithelialization by the 7th day, and in 100 per cent of the patients by the 21st day. In wounds treated with silver sulfadiazine, epithelialization occurred by the 7th day in 72 per cent of the patients and in 84 per cent of patients by 21 days. Histological evidence of reparative activity was seen in 80 per cent of wounds treated with the honey dressing by the 7th day with minimal inflammation. Fifty two per cent of the silver sulfadiazine treated wounds showed reparative activity with inflammatory changes by the 7th day. Reparative activity reached 100 per cent by 21 days with the honey dressing and 84 per cent with SSD. Thus in honey dressed wounds, early subsidence of acute inflammatory changes, better control of infection and quicker wound healing was observed while in the SSD treated wounds sustained inflammatory reaction was noted even on epithelialization.

Administration, Topical↗
PubMed1996

Epidemiology of burns in a district hospital in western India.

In a prospective study, data on 175 patients treated between June 1993 and February 1994 has been analysed. In this series, adolescents and young adults (11-40 years) comprised 79.4 per cent of the patients. Males formed 43 per cent and females 57 per cent of the total burns 92 per cent of the burns occurred at home. 86.8 per cent of the patients belonged to low socioeconomic groups. 47.4 per cent of them were housewives or housemaids. 44.6 per cent of burns occurred during the morning hours from 6 a.m. to 12 noon. 79.4 per cent of the burns were accidental in nature. Flame burns accounted for 92 per cent, scalds for 5.7 per cent of the total. 64.5 per cent of the patients were admitted within 4 h of injury. The overall mortality rate was 56.5 per cent, below 40 per cent surface area burned (%BSAB) it was 6.1 per cent and above 70 per cent it was 100 per cent. Flame burns resulted in maximum deaths (86.1 per cent). 40 per cent of the patients had more than 70 per cent BSAB burns in this series, which accounts for the high mortality.

Adolescent↗
PubMed1996

Honey dressing versus boiled potato peel in the treatment of burns: a prospective randomized study.

Honey dressing was compared with boiled potato peel dressings as a cover for fresh partial-thickness burns in two groups of 50 randomly allocated patients. In the 50 patients treated with honey, 90 per cent of wounds were rendered sterile within 7 days. In the 50 patients treated with boiled potato peel dressings, persistent infection was noted within 7 days. Of the wounds treated with honey, 100 per cent healed within 15 days as against 50 per cent in the wounds treated with boiled potato peel dressings (mean 10.4 vs. 16.2 days).

Adolescent↗
PubMed1995

Amniotic membrane as a cover for microskin grafts.

Twenty two granulating wounds were grafted with microskin grafts of 1 mm size and amniotic membrane was used to cover these grafts. In 16 patients, epithelialisation was complete by 10 days and the grafts remained stable. Fifteen-fold expansion was achieved in all these cases. The remaining 6 patients needed split thickness skin grafts due to failure of the microskin grafts. Human amniotic membrane as a cover for microskin grafts helped early epithelialisation and rapid wound healing.

Adolescent↗
PubMed1994

Honey-impregnated gauze versus amniotic membrane in the treatment of burns.

A prospective randomized clinical study to compare honey-impregnated gauze with amniotic membrane dressing in partial thickness burns was carried out. Sixty-four patients were studied. Forty of them were treated with honey-impregnated gauze and 24 were treated with amniotic membrane. The burns treated with honey healed earlier as compared to the amniotic membrane (mean 9.4 vs 17.5 days) (P < 0.001). Residual scars were noted in 8 per cent of patients treated with honey-impregnated gauze and in 16.6 per cent of cases treated with amniotic membrane (P < 0.001).

Adolescent↗
PubMed1993

Role of surgery and chemotherapy for peripheral lymph node tuberculosis.

A total of 105 patients with peripheral lymph node tuberculosis were treated by either surgical excision and chemotherapy or chemotherapy alone. The cervical nodes were affected in 98 patients, axillary nodes in four and inguinal nodes in three. Biopsy of the lymph nodes confirmed the diagnosis in all cases. Thirty-five patients who had sinus, ulcer or abscess underwent excision of the lymph nodes with drainage of the abscess, or resection of the sinus or ulcer. The remaining 70 patients received only chemotherapy. Chemotherapy in all patients consisted of isoniazid and ethambutol for 18 months. Of the 35 patients treated with surgery and chemotherapy, two had gaping wounds, one infection and one cellulitis of the face and neck. After 3 months, one patient had recurrence of the lymph node mass and one recurrence of a sinus; these were excised. Of the 70 patients treated only with chemotherapy, 13 were lost to follow-up. Four had non-healing wounds at the biopsy site, six wound infection and two sinus formation. Five of these patients had persistent lymph node masses, which were excised after 3 months. The remaining 52 patients had no recurrence.

Adolescent↗
PubMed1992

Mesosigmoplasty as a definitive operation for sigmoid volvulus.

In a prospective study, 126 patients with sigmoid volvulus were treated by mesosigmoplasty during a 12-year period. Patients with sigmoid volvulus with no clinical evidence of gangrene were selected for study, and all were given a trial of non-operative reduction by proctoscopy and passage of a rectal tube. Reduction was achieved in 48 patients (38 per cent), who were subsequently treated by mesosigmoplasty as an elective procedure 1-2 weeks later. For the remaining 78 patients (62 per cent) who were not relieved by the non-operative method, emergency mesosigmoplasty was performed. There was one death in the emergency group, and two patients had a recurrence after 2 and 6 months respectively in the elective group, in whom resection was carried out. In the other 123 patients during a maximum follow-up of 12 (mean 8.2) years no recurrence was detected. Mesosigmoplasty has the advantage of low rates of mortality, morbidity and recurrence; it can be carried out as either an emergency or an elective procedure.

Adult↗
PubMed1991

Topical application of honey in treatment of burns.

A total of 104 cases of superficial burn injury were studied to assess the efficiency of honey as a dressing in comparison with silver sulfadiazine gauze dressing. In the 52 patients treated with honey, 91 per cent of wounds were rendered sterile within 7 days. In the 52 patients treated with silver sulfadiazine, 7 per cent showed control of infection within 7 days. Healthy granulation tissue was observed earlier in patients treated with honey (mean 7.4 versus 13.4 days). Of the wounds treated with honey 87 per cent healed within 15 days as against 10 per cent in the control group. Relief of pain, a lower incidence of hypertrophic scar and postburn contracture, low cost and easy availability make honey an ideal dressing in the treatment of burns.

Administration, Topical↗