Studies on Pongamia pinnata (L.) Pierre leaves: understanding the mechanism(s) of action in infectious diarrhea.

While data are available on the effect of medicinal plants on intestinal motility and their antibacterial action, there is a paucity of information on their mode of action on various aspects of diarrheal pathogenicity, namely colonization to intestinal epithelial cells and production/action of enterotoxins. Crude decoction of dried leaves of Pongamia pinnata was evaluated for its antimicrobial (antibacterial, antigiardial and antirotaviral) effect; and its effect on production and action of enterotoxins (cholera toxin, CT; Escherichia coli labile toxin, LT; and E. coli stable toxin, ST); and adherence of enteropathogenic E. coli and invasion of enteroinvasive E. coli and Shigella flexneri to epithelial cells. The decoction had no antibacterial, antigiardial and antirotaviral activity, but reduced production of CT and bacterial invasion to epithelial cells. The observed results indicated that the crude decoction of P. pinnata has selective antidiarrheal action with efficacy against cholera and enteroinvasive bacterial strains causing bloody diarrheal episodes.

Clinical, histopathological and bacteriological study of 52 referral MB cases relapsing after MDT.

Fifty-two BB-LL relapse cases referred to our centre during 1997-2003 were investigated in detail. Twenty-four cases had been treated with extended MB-MDT [until smear negativity (NON-FDT)]. The remaining 28 cases (54%) had received one of the fixed duration regimens (FDT), of whom 11 had 24 months and 6 had 12 months of WHO MB-MDT. Eleven cases had received rifampicin/ofloxacin (RO) treatment. Follow-up slit skin smear reports were available for 41 cases, all but three cases had been smear negative at some point after release from treatment. None of the cases showed any clinical or bacteriological evidence of upgrading, i.e. LL to BT where as downgrading BB to BL occurred in five cases. The duration between cessation of treatment and reappearance of lesions (DCTR) varied from 2 to 15 years. The mean DCTR was longest (9.4 years) for the NON-FDT and 24 months MB-MDT cases. The mean DCTR was significantly lower in the 12 months MB-MDT and RO treated cases (6.8 and 6.2 years, respectively). Four of RO treated cases and four cases with multiple episodes of reaction had DCTR less than 5 years. Inadequate treatment/poor killing of Mycobacterium leprae results in early onset relapse, whereas 'persisting' or 'drug resistant mutants' contribute to late onset relapse.

Effect of Mycobacterium leprae-infected Schwann cells and their supernatant on lymphocyte neuroglia interaction.

Since the resolution of neural lesions and subsequent nerve damage in leprosy must inevitably involve the participation of immune cells sensitized to Mycobacteria, we have used the dissociated Schwann cell culture model to study the relationship between M. leprae-infected Schwann cells and sensitized immune cells. Our earlier study on light and ultrastructural observations showed that on infection with M. leprae, the cytomorphology of Schwann cells remains unaffected, while degenerative changes suggestive of apoptosis are seen in extraneous lymphocytes which are subsequently phagocytosed by the Schwann cells. We now present additional evidence confirming that the phagocytosis of splenic cells by Schwann cells is indeed a two-step process. The first involves M. leprae-dependent cytotoxicity to splenic cells. This is followed by phagocytosis of these cells, which is a secondary and M. leprae-independent phenomenon. This finding has implications particularly on the weak inflammatory response observed in nerve lesions of a majority of lepromatous patients.

Adherence of Mycobacterium leprae to Schwann cells in vitro.

Adherence of Mycobacterium leprae was studied in vitro in monolayer cultures of purified mouse Schwann cells. The optimum temperature and time for adherence were determined. Pretreatment of Schwann cells with lipase reduced adherence, but pretreatment with trypsin enhanced it and with four monosaccharides--L-arabinose, L-galactose, L-rhamnose and D-glucose--there was no significant effect, indicating that the receptors involved in adherence may be lipid.

The pathology of early leprous neuropathy.

A qualitative and quantitative study was made of early changes in nerves from 10 patients with tuberculoid or lepromatous type of leprosy. Five nerve biopsies, taken from sites remote from skin lesions, were considered to be unaffected when examined by paraffin histology but showed abnormalities in semi-thin resin sections and by electron microscopy; 5 showed mild to moderate involvement by paraffin histology. Changes in 'unaffected' nerves in both types of leprosy included the presence of subperineurial oedema; occasional evidence of fibre regeneration, sometimes with atypical features; increased numbers of small myelinated fibres, possibly a consequence of axonal atrophy; a few thinly remyelinated fibres, probably due to secondary demyelination, and some loss of unmyelinated axons. In more affected nerves there was variable loss of axons, both myelinated and unmyelinated. Demyelination was not a conspicuous feature; there was evidence of axonal atrophy in some fibres. Similarities in some of the changes observed in tuberculoid and lepromatous types of leprosy suggest a common mechanism of nerve damage, at least in the early stages. The presence of abnormalities in nerves at a distance from skin lesions implies a more diffuse nerve involvement than might have been expected in both types of leprosy.

Teased fibre studies in leprous neuropathy.

Nerve biopsies were taken from four cases of leprosy, which included borderline tuberculoid, borderline and lepromatous types. They were examined in 1-micron resin sections and in teased preparations. The most common finding in teased fibres from each leprosy type was paranodal demyelination affecting successive internodes. In transverse sections some fibres showed changes associated with axonal atrophy. Together, these findings suggest that demyelination in some cases may be secondary to axonal changes. In addition, there was evidence of focal areas of demyelination affecting whole internodes of many fibres at the same level across the nerve and which was possibly caused by local factors.

Schwann cell extracellular matrix protein production is modulated by Mycobacterium leprae and macrophage secretory products.

Extracellular matrix (ECM) protein deposition is an important feature of leprous nerves, where Schwann cells (SCs) and macrophages are the main hosts for Mycobacterium leprae. Since, SCs are involved in the synthesis of ECM proteins and its production is regulated by macrophage secretory factors, the present study aimed to determine in vitro, the effect of M. leprae infection and macrophage secretory products on secretion of ECM proteins by SCs in two strains of mice, Swiss White (SW) and C57BL/6, that are known to differ in their nerve pathology and macrophage functions in response to infection. Following six days of M. leprae infection, SCs from SW mice responded with increased secretion of 14C-leucine radiolabelled proteins and a concomitant increase in laminin and collagens type I, III and IV, as determined by enzyme-linked immunosorbent assay. In contrast infected C57BL/6 SCs responded with decreased secretion of total proteins and fibronectin. Exposure of SCs to macrophage conditioned medium resulted in decreased ECM protein secretion in both strains of mice. This decrease was a function of protein breakdown by macrophage derived proteases and also active regulation by macrophage secreted cytokines. A similar effect of M. leprae and macrophage secretory products on SC metabolism in leprous nerves would have major ramifications on damage and repair activities. In addition ECM proteins would also influence the composition of the infiltrating cell population in lepromatous and tuberculoid nerves.

Plastic footwear for leprosy.

The anaesthetic foot in leprosy poses the most major problem in the rehabilitation of its patients. Various attempts have been made to produce protective footwear such as the microcellular rubber-car-tyre sandals. Unfortunately these attempts have had little success on a large scale because of the inability to produce them in large numbers and the stigma attached to such unusual footwear. While such footwear may be superior to the 'tennis' shoe in protecting the foot from injury by the penetration of sharp objects, it fails to distribute the weight-bearing forces which is the major cause of plantar damage and ulceration in the anaesthetic foot. This can be achieved by providing rigidity to the sole, as demonstrated by the healing of ulcers in plaster of paris casts or the rigid wooden clog. A new type of moulded plastic footwear has been evolved in conjunction with the plastic footwear industry which provides footwear that can be mass produced at a low price and which overcomes the stigma of leprosy. Controlled rigidity is provided by the incorporation of a spring steel shank between the sponge insole and the hard wearing plastic sole. Trials have demonstrated both the acceptability of the footwear and its protective effects as well as its hard wearing properties.

Vascular surgery of the posterior tibial compartment for plantar ulceration in leprosy.

Traditional surgical decompression of the posterior tibial nerve yields equivocal results. The authors postulate that the posterior tibial artery is the most compromised structure in the neurovascular compartment and that the best surgical results in healing of plantar ulcers are achieved by the rechannelling of the blood flow in the posterior tibial artery during posterior tibial neurovascular compartment surgery. This procedure has been of benefit to patients with plantar ulcers of greater than 7-10 years' duration in whom all other modes of healing had failed. It has been undertaken as an outpatient procedure under local anaesthesia, supported by postoperative vasodilator drugs. The use of tourniquet, antibiotics and surgical interference with the ulcer per se was eschewed. A report of 156 patients is presented with follow-up of up to 6 years for the earlier cases.

Higher incidence of viable Mycobacterium leprae within the nerve as compared to skin among multibacillary leprosy patients released from multidrug therapy.

As identified by a significant growth in the footpads of immunosuppressed mice, the incidence of viable bacteria in a group of 26 multibacillary (BL-LL) patients released from multidrug (MDT) treatment was found to be two times more in the nerves (46%) as compared to skin (23%). Evidently there was a positive correlation between the overall bacterial load and the incidence of viable organisms. Bacterial growth was also observed in two out of five cases where neither the skin nor the nerve homogenate had shown any presence of acid-fast bacilli. Histopathology of biopsies, skin as well as nerve, including those having viable bacteria did not show any features of active disease.

Persistence of Mycobacterium leprae in the peripheral nerve as compared to the skin of multidrug-treated leprosy patients.

Skin and nerve biopsies obtained from 18 multibacillary (MB) and 16 paucibacillary (PB) cases of leprosy who had been fully treated by the WHO regimen were assessed for bacterial load using different staining techniques. In addition skin and nerve homogenates of 10 MB cases were tested for 'persistor' Mycobacterium leprae using immunosuppressed mice. While significant amounts of integral bacilli and BCG cross-reactive antigen of M. leprae were detected both in skin and nerve tissues of all the MB cases (100%), 56% of skin and 62% of nerve biopsies of PB cases also showed the presence of BCG cross-reactive antigen. Detection of 'persistor' M. leprae in 2/10 skin biopsies (20%) and 3/10 nerve biopsies (30%) of MB cases was thought to be unexpectedly high after 2 years of MDT.

Primary resistance to single and multiple drugs in leprosy--a mouse footpad study.

Skin biopsy homogenates obtained from three cases of lepromatous leprosy with no prior history of antileprosy treatment were tested in the mouse footpad for the sensitivity of Mycobacterium leprae to multiple drugs. One of the inocula was sensitive to all the three drugs tested using the highest concentration each of DDS 0.01 g%, RFP 0.03 g% and CLF 0.01 g%. The 2nd inocula showed growth in the presence of 0.01 g% DDS only. While the 3rd inocula (Pt. KU) tested resistant to all the three drugs in the first, i.e. man to mouse, as well as in the second passage, i.e. mouse to mouse.

Clinical and electrophysiological evaluation of nerve function impairment following cessation of multidrug therapy in leprosy.

Seventeen multibacillary (MB) and 15 paucibacillary (PB) cases of leprosy who had had regular and adequate multidrug therapy (MDT) were examined clinically and electrophysiologically at periodic intervals for 1 year following cessation of MDT. All the major nerves were assessed for nerve function impairment (NFI). Overall, two MB (13.3%) and three PB (20%) cases showed signs of deterioration clinically and/or electrophysiologically. The nerve conduction (NC) follow-up studies revealed no significant improvement in the sensory conduction in both the MB and PB groups of nerves, whilst motor conduction showed a significant improvement at the first 6-monthly follow-up among the MB group of nerves. At the study onset, sensory impairment (MB = 62%, PB = 25%) predominated over motor in terms of both severity and frequency. The lower extremity was more frequently and severely affected than the upper in both groups of patients. As an individual test, NC measurement proved to be more sensitive in detecting NFI, but the combination of physical palpatation for nerve thickening and graded nylon test (GNT) was closely comparable to measurement of nerve conduction.

In vitro studies on extracellular matrix production by M.leprae infected murine neurofibroblasts.

Fibroblasts and a host of macrophage secretory products have been implicated in a number of diseases where excess extracellular matrix (ECM) deposition is the main pathological feature. Fibrosis characterized by excessive deposition of collagen also contributes to the irreversible nerve damage observed in leprosy. Since M. leprae are seen within neurofibroblasts (Nf) in the advanced stages of the disease and macrophages form a common infiltrating cellular constituent of leprous nerves at all stages, secretion of ECM proteins by Nf was studied, in vitro following infection with M. leprae and in the presence of macrophage secretory products. These studies were compared in cells derived from two strains of mice, Swiss White (SW) and C57BL/6, as they differ in their response to M. leprae infection and parallel those observed in lepromatous and tuberculoid patients, respectively. On infection with M. leprae, Nfs showed a decrease in secretion of collagen type IV in SW and type I in C57Bl/6 strain. Macrophages caused a further decrease in the secretion of collagen types affected by M. leprae infection per se, while the other collagen types, viz. I and III in SW strain and III and IV in C57Bl/s strain, were unaffected. This study indicates that neural collagenization in nerves in advanced leprosy may be of Nf origin. However, unlike other diseases with excess collagen deposition, ECM proteins produced by Nfs in response to nerve damage may not be of prime importance in the progression of leprous neuropathy and occur as a general response to loss of cellular content in leprous nerves.

Views on the sustenance of resistant Mycobacterium tuberculosis in the environment.

Microbial resistance to conventional as well as newly introduced drugs is a hallmark feature of several infectious diseases, notably tuberculosis. It is hypothesized that the greater the selective pressure exerted by increasingly potent drugs, the more rapidly is an organism able to adapt to a drug-containing environment. The roles of drug-containing environments, and the immunological status of the host and bacterial molecular mechanisms of development of drug resistance to Mycobacterium tuberculosis have been examined and examples cited for implementation of modified drug regimens in tuberculosis-control programmes. The views expressed, albeit restricted to Mycobacterium tuberculosis, encourage consideration of drug regimens on a disease evolution basis as well as understanding of the natural rules that govern development and sustenance of drug resistance in the microbial world.

"Malignant" contracture of the eye socket.

A new method for reconstruction of "malignant" contracture of the eye socket is described using a simple procedure based on the principle of epithelial inlay. The lining consists of a free skin graft. No cumbersome external appliances for the prevention of contraction of the graft are used; hence the hospitalization is minimized. The results have been satisfactory.

Large Indian forehead rhinoplasty. Case report.

The classic Indian rhinoplasty, with a midline forehead flap, was performed on 4 young adult patients with "cut noses". The rather large flaps survived in all cases, without a delay procedure, and the results were surprisingly good. The appearance of the donor area is, however, a problem-especially in patients with pigmented skins. The method is relatively simple and we believe it to be of value in selected cases.

Surgical treatment of the nasal deformities of leprosy: a 16-year review.

We present a retrospective review (from 1959 to 1975) of 86 patients who were treated surgically for nasal leprosy deformities at the Tata Department of Plastic Surgery. The postnasal skin graft inlay was the most frequent procedure, and it seems best suited for these repairs in developing countries where the patients often present late with major deformities. For minor and early nasal deformities, the insertion of a bone graft or a silicone rubber implant is recommended.

Simple methods for disinfecting household drinking water.

BACKGROUND: The methods commonly used for disinfecting drinking water are either too expensive or impractical for use in villages and urban slums. METHODS: We have devised two simple and cost-effective methods for disinfecting drinking water using solar heat and the normally unutilized heat from the traditional Indian mud stove or chulha. RESULTS: Using these methods water temperatures of 60°C were attained which successfully disinfected water contaminated artificially with E. coli (120 organisms per ml) after 3 hours. CONCLUSION: This simple technique of disinfecting water may be acceptable on a large scale.

Leprosy control by a people's program: "a new concept in technology transfer".

Leprosy is a major health hazard in tropical countries as it also is in China. All programs for the control of this disease have been based on the cheap, effective, and low-toxicity antileprosy drug Dapsone (DDS), available since the early 1950s. The emphasis has been on early detection and regularity of treatment, which has to be maintained for several years, if not a lifetime. Despite the availability of what might be rightly termed the "magic bullet," World Health Organization (WHO) figures demonstrate that leprosy has not been controlled in most countries and is generally on the increase. Blame has been ascribed to the patients for hiding the disease and for irregularity of treatment. Emphasis has now shifted to high-technology research to evolve more expensive and much more difficult multidrug regimens and an antileprosy vaccine. China, isolated from the rest of the world and using only simple DDS therapy, but ensuring its use through its barefoot doctor approach, has shown a reduction of leprosy cases from 500,000 to 100,000 in the past three decades. The author suggests that the world, including WHO, should learn from the experience of China rather than try to impose its own low effective and more expensive high-technology approach on this country.