Microcellular polyHIPE polymer supports osteoblast growth and bone formation in vitro.

A novel micro-cellular polymer with a well-defined and uniform micro-architecture has been developed as a three-dimensional support matrix for in vitro tissue engineering applications. This material is manufactured through a high internal phase emulsion (HIPE) polymerization route and may be modified with hydroxyapatite. The generic form of the support is known as PolyHIPE Polymer (PHP). By changing the chemical composition of the emulsion and the processing conditions, the pore size can be altered from sub-micron range to a few hundred microns and the porosity varied from 70% to 97%. Our work has investigated the use of this micro-porous polymer as a biomaterial to support the growth of osteoblasts, the bone forming cells in vitro. Three groups of polymers were used that had pore sizes of 40, 60 and 100 microm. Results demonstrated in vitro cell-polymer compatibility, with osteoblasts forming multicellular layers on the polymer surface and also migrating to a maximum depth of 1.4mm inside the scaffold after 35 days in culture. PHP was also able to support the differentiation of osteoblasts and the production of a bone-like matrix. The effect of modifying the polymer with hydroxyapatite was also studied and showed that there was a significant increase in osteoblast numbers penetrating into the polymer. There were few differences, between the pore sizes studied, on the overall penetration of osteoblasts into the polymer but the rate of movement into 100 microm PHP was significantly higher compared to the other sizes investigated. This study shows that osteoblasts seeded onto PHP demonstrate cellular attachment, proliferation and ingrowth leading to the support of an osteoblastic phenotype. Therefore this highly porous scaffold has a potential for bone tissue engineering.

Tinea unguium in Lahore, Pakistan.

During a period of 1 year, out of 202 clinically suspected cases of tinea unguium, 53 (26%) were confirmed by mycological cultures for dermatophytes. Trichophyton rubrum was the most common fungus isolated in 46 (87%) patients, followed by T. violaceum in four (7%), T. interdigitale in two (4%) and Epidermophyton floccosum in one (2%). The disease was more common in adult males and fingernails were found to be affected more often than toenails. The distal and lateral variety was seen in 41 (77%) patients, total secondary dystrophic type in 11 (21%) and proximal subungual type in one (2%). Clinical diagnosis alone is not reliable and mycological confirmation is mandatory for this potentially curable disease.

Onychomycosis in Lahore, Pakistan.

BACKGROUND: Onychomycosis, a common nail disorder, is caused by yeasts, dermatophytes, and nondermatophyte molds. These fungi give rise to diverse clinical presentations. The present study aimed to isolate the causative pathogens and to determine the various clinical patterns of onychomycosis in the population in Lahore, Pakistan. PATIENTS: In 100 clinically suspected cases, the diagnosis was confirmed by mycologic culture. Different clinical patterns were noted and correlated with causative pathogens. RESULTS: Seventy-two women (mean age, 32.6 +/- 14.8 years) and 28 men (mean age, 40.6 +/- 15.8 years) were studied. Fingernails were involved in 50%, toenails in 23%, and both fingernails and toenails in 27% of patients. The various clinical types noted were distolateral subungual onychomycosis (47%), candidal onychomycosis (36%), total dystrophic onychomycosis (12%), superficial white onychomycosis (3%), and proximal subungual onychomycosis (2%). Candida was the most common pathogen (46%), followed by dermatophytes (43%) (Trichophyton rubrum (31%), T. violaceum (5%), T. mentagrophytes (4%), T. tonsurans (2%), and Epidermophyton floccosum (1%) and nondermatophyte molds (11%) (Fusarium (4%), Scopulariopsis brevicaulis (2%), Aspergillus (2%), Acremonium (1%), Scytalidium dimidiatum (1%), and Alternaria (1%). CONCLUSIONS: Onychomycosis is more common in women of 20-40 years of age. Distolateral subungual onychomycosis and candidal onychomycosis are the most common clinical presentations, and Candida and T. rubrum are the major pathogens in Pakistan.

Locally advanced rectal cancer with a pelvic kidney complicating adjuvant radiation therapy.

The simultaneous occurrence of colorectal malignancy with pelvic kidney is unusual. We report a case of locally advanced rectal cancer stage III disease, T3N2M0, with a pelvic kidney complicating adjuvant radiation therapy. We recommend preoperative evaluation of the pelvic kidney to allow for its protection by translocation or heterotopic autologous transplantation. Occasionally a nephrectomy may be necessary. Otherwise extended lymph node dissection is not performed; hence, adequate treatment of the primary rectal cancer is compromised. The sequela of inadequate surgical excision and suboptimal radiation therapy is early relapse.

Diverticular hemorrhage in the elderly--is it well tolerated?

PURPOSE: Elderly patients frequently develop lower gastro-intestinal bleeding secondary to diverticulosis. This select group of patients potentially tolerates blood loss poorly, often have coexisting cardiovascular morbidity, and may not tolerate surgical intervention. Thus, optimal management of elderly patients with diverticular hemorrhage remains difficult. METHODS: All patients who were admitted with the diagnosis of diverticulosis at the St. Louis University affiliated hospitals during the past 60 months were identified. Those with diverticular bleeding were extracted. Patients were reviewed as to age, sex, diagnosis of diverticular bleeding, number of bleeding episodes, lowest hemoglobin before transfusion, amount of blood received, treatment, operations, the presence of recurrent bleeding, morbidity, and mortality. RESULTS: One hundred fifteen consecutive patients, age 70 years admitted with lower gastrointestinal hemorrhage secondary to diverticulosis who required transfusion, were identified. Mean age was 79 years; 26 of 115 (23 percent) were more than 80 years of age; 78 of 115 (54 percent) were males; 39 of 115 (34 percent) had more than one previous admission for diverticular hemorrhage. The mean serum hemoglobin was 8.9 g/dl. All patients underwent colonoscopy; 34 of 115 (29 percent) underwent 99Tc scanning, of which 18 of 34 (54 percent) underwent arteriogram. Seven of 18 (39 percent) demonstrated extravasation secondary to bleeding diverticulosis. The mean transfusion requirement was 2.8 (range, 1-17) units; 21 of 115 (18 percent) required intestinal resection; 2 of 21 (9 percent) experienced a 30-day mortality. Among those, 94 of 115 were treated without surgery, and 3 of 94 (4 percent) died. Mortality was independent of initial hemoglobin (P = 0.21), previous diverticular hemorrhage (P = 0.44), amount of blood transfused (P = 0.36), and type of treatment (0.09). CONCLUSIONS: Most diverticular bleeding in the elderly is well tolerated using nonoperative management. Success and safety of treatment does not seem to depend on a history of previous diverticular bleeding, initial hemoglobin, or amount of blood transfused. The majority of patients are treated nonoperatively. Surgical intervention seems to be well tolerated.

Control of myofibrillar ATPase activity and force in myodystrophic muscle.

Myofibrillar ATPase activity was measured as a function of the free calcium concentration in skeletal muscles of control and myodystrophic mice. In addition, the force developed in skinned extensor digitorum longus (EDL) fibers of control and myodystrophic mice was measured as a function of the free calcium concentration, and a histomorphometric study was performed on soleus and EDL muscles of control and myodystrophic mice. The results showed that the myofibrillar ATPase activity and the force-generating mechanisms of control and myodystrophic muscles were controlled to the same relative degree by equivalent concentrations of calcium ions. Upon maximal activation of the ATPase activities, we measured 18% less activity in myodystrophic muscles than in control muscles. Maximal activation of the force-generating capacity in skinned fibers showed there was no significant difference in force produced in the control compared to myodystrophic fibers. The histomorphometric study revealed no alteration in the relative distribution of different fiber types in myodystrophic compared to control muscles. However, the histomorphometry did reveal a larger slow (type 1) relative cellular area compared to total cross-sectional area in myodystrophic muscle than in controls. We propose that the lower ATPase activity but equal force-generating capacity of myodystrophic muscles compared to control muscles is due to myodystrophic muscles being composed of a greater fraction of myofibrils from slow (type 1) fibers than control muscles.