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Biomedical subjects

T Mahmood

Publications and source records attributed to T Mahmood.

At least 55 records · Page 3Linked to original sources

Urticaria.

Urticaria (hives) is a common disorder that affects 15 to 20 percent of the population at some time. Lesions are clinically characterized by a transient, pruritic, patchy eruption that consists of lightly erythematous papules or wheals. When attacks are protracted, urticaria is an annoying condition for the patient and a challenge for the physician. Foods, drugs and many other agents may cause urticaria by inducing mediator release from mast cells in the skin. Identification of the precipitating agent is crucial for effective treatment of urticaria. Newer antihistamines that are nonsedating offer promise for control of symptoms without the problem of frequent side effects.

Humans↗

Physical urticarias.

Chronic urticaria can be produced by a number of stimuli that cause mast cell mediator release. Patients with urticaria caused by physical agents account for roughly one-fifth of all cases of chronic urticaria. There are about 20 different types of physical urticaria. Two forms, dermographism and cholinergic urticaria, are quite common and represent more than two-thirds of all cases of physically caused urticaria. More than one agent may precipitate urticaria in a given individual. Urticarial response can be easily reproduced in the sensitive patient and, generally, lasts less than one hour. Systemic features such as flushing, dizziness, headaches, and even hypotension, may occur during severe episodes. Identification of the causative physical agent is necessary for effective therapy.

Humans↗

Growth and ovarian function of weanling and yearling beef heifers grazing endophyte-infected tall fescue pastures.

Growth and ovarian function of crossbred beef heifers grazing low and high endophyte-infected tall fescue pastures were studied for 2 successive years. In April of each year, 20 weanling and 20 yearling heifers were included in the study. All heifers were weighed at 28-d intervals for 112 d. Blood samples were collected from each heifer on Day 0 and +7 of each of five 28-d periods and analyzed for progesterone concentration. Heifers with progesterone concentrations >/= 1.5 ng/ml on either or both Day 0 and +7 were classified as having normal cyclic ovaries. High endophyte-infected fescue pastures adversely altered the ovarian activity (P < 0.05) of weanling heifers in both years. In each trial, average weight gains were lower (P < 0.05) in yearling and weanling heifers grazing the high endophyte-infected pastures than in heifers grazing low endophyte-infected pastures. In 1992, heifers were synchronized with PGF(2alpha) administered on Days 101 and 112. Blood samples were collected on 0, 4, 8 and 12 d after the second PGF(2alpha) injection for progesterone analysis. Heifers grazing high and low endophyte-infected pastures were pastured separately with 4 bulls each and were given heatmount detectors. At 96 h, less estrus activity was observed (P < 0.10; power=0.63) in weanling heifers grazing the high vs. low endophyte pastures although pregnancy rates were similar for all groups. Progesterone concentrations suggested that weanling heifers on the high endophyte pastures had a higher incidence of luteal dysfunction after PGF(2alpha) synchronization. In summary, high endophyte-infected pastures decreased growth in both weanling and yearling heifers, ovarian activity and luteal function were adversely altered in weanling heifers with subsequent decreased estrus response to estrus synchronization.

Journal Article↗

Management of prelabour rupture of the membranes in term primigravidae: report of a randomized prospective trial.

OBJECTIVE: To compare a conservative and an active policy (immediate oxytocin infusion) of management of prelabour rupture of the membranes in term primigravidae. DESIGN: Randomized trial involving 444 women. SETTING: District maternity hospital. MAIN OUTCOME MEASURES: Caesarean section rate in each group; also the rate of forceps deliveries, spontaneous deliveries, length of labour, number of vaginal examinations, type of analgesia, pyrexia in labour or the puerperium and antibiotic use in the mother and the infant in each group. The caesarean section rate for the whole trial where the latent period was greater than 12 h was compared to that where the latent period was less than or equal to 12 h. RESULTS: There were fewer caesarean sections in the conservative group (odds ratio (OR) 0.60, 95% confidence interval (CI) 0.35 to 1.02; P = 0.06). There was a similar number of forceps deliveries (OR 0.79; 95% CI 0.52 to 1.19; P = 0.26) but more spontaneous deliveries (OR 1.57; 95% CI 1.08 to 2.29; P = 0.02) in the conservative group. More women managed conservatively required inhalational analgesia only for pain relief in labour (OR 2.88; 95% CI 1.46 to 5.68; P = 0.003), a similar number required pethidine (OR 1.29; 95% CI 0.85 to 1.94; P = 0.23), and fewer required epidural analgesia (OR 0.57; 95% CI 0.39 to 0.84; P = 0.005). The number of vaginal examinations was less in the conservative group (difference between mean 0.53; 95% CI 0.25 to 0.80; P less than 0.001). Fewer women managed conservatively experienced four or more vaginal examinations in labour (OR 0.58; 95% CI 0.39 to 0.86; P = 0.007). There were no differences in the lengths of labour, the proportions of women who developed pyrexia in labour or the puerperium or who required antibiotics or in the proportions of infants who required antibiotics. CONCLUSIONS: These results argue in favour of a conservative policy in managing primigravidae at term with prelabour rupture of the membranes.

Adult↗

Home-based intravenous therapy for oncology patients.

It is desirable to keep cancer patients at home whenever possible to maximize their physical comfort and mental well-being. However, physicians should be aware of all the serious limitations in terms of patient selection and avoidance of the abuses of overutilization of the system.

Antineoplastic Agents↗

Detection of anti-basement membrane zone antibodies in bullous systemic lupus erythematosus.

We describe a 42-year-old black woman with long-standing systemic lupus erythematosus in whom vesiculobullous lesions developed. Routine histologic and immunologic studies fulfilled the criteria for the diagnosis of bullous systemic lupus erythematosus. Indirect immunofluorescence showed antinuclear antibodies without basement membrane zone fluorescence. We destroyed the nuclear antigens of the indirect immunofluorescence substrate with 2 mol/L sodium chloride, which unmasked basement membrane zone linear IgG staining. We also confirmed anti-basement membrane zone antibodies by employing a new technique of direct immunofluorescence on sodium chloride-split skin. Our finding prove that a thorough search for anti-basement membrane zone antibodies can be revealing. Our results support the idea that a subset of bullous systemic lupus erythematosus has the staining characteristics of epidermolysis acquisita, with the dermal side of the split skin showing linear immunoglobulin deposition.

Adult↗

Elevated sacroiliac joint uptake ratios in systemic lupus erythematosus.

Sacroiliac joint radiographs and radionuclide sacroiliac joint uptake ratios were obtained on 14 patients with active systemic lupus erythematosus. Elevated joint ratios were found unilaterally in two patients and bilaterally in seven patients when their lupus was active. In patients whose disease became quiescent, the uptake ratios returned to normal. Two patients had persistently elevated ratios with continued clinical and laboratory evidence of active lupus. Mild sacroiliac joint sclerosis and erosions were detected on pelvic radiographs in these same two patients. There was no association between low back pain or HLA-B27 positivity and the radiographic or scintigraphic abnormalities. Elevated quantitative sacroiliac joint uptake ratios may occur as a manifestation of active systemic lupus erythematosus.

Adult↗

Modulation of venom-induced leukocyte histamine release by mononuclear cells: effect of venom immunotherapy.

Leukocyte histamine release and blood mononuclear cell proliferative responses to venoms were evaluated in nine patients with sting anaphylaxis. The effect of venom-activated mononuclear cells on the autologous mononuclear cell proliferative response and venom-induced leukocyte histamine release was also studied before and on maintenance immunotherapy. The mononuclear cell proliferative response was low (specific incorporations less than 2.0) and antigen nonspecific both before and during maintenance immunotherapy. Venom-induced in vitro leukocyte histamine release did not change significantly with immunotherapy. However, when patients were on maintenance immunotherapy, venom-activated mononuclear cells cocultured with autologous leukocytes significantly (p less than 0.05) suppressed venom-induced histamine release. The suppressive effect of mononuclear cells was antigen specific and enhanced by in vitro mononuclear cell activation. Suppression of leukocyte histamine release by mononuclear cells extends the regulatory potential of these cells and may identify an additional mechanism by which immunotherapy protects Hymenoptera-sensitive individuals against systemic anaphylaxis.

Adult↗

Extension of myeloid tissue into the lower extremities in polycythemia.

Biopsies of the posterior iliac crest, greater trochanter, and proximal tibia were done for 27 polycythemic patients before myelosuppressive therapy was begun. Five had relative polycythemia, thirteen had secondary polycythemia, and nine had polycythemia vera. None of five biopsy specimens of the greater trochanter in cases of relative polycythemia contained myeloid tissue (erythroblasts, granulocytic precursors, and megakaryocytes). Four of six biopsy specimens of the greater trochanter and one of eight of the tibia in cases of secondary polycythemia contained myeloid tissue. All seven biopsy specimens of the greater trochanter and two of five biopsy specimens of the proximal tibia in cases of polycythemia vera contained myeloid tissue. A trochanter biopsy specimen devoid of myeloid tissue probably eliminates the diagnosis of polycythemia vera. Myeloid tissue extends from the axial skeleton to the greater trochanter, therafter to the tibia. Extension of myeloid tissue does not imply that marrow failure is imminent in polycythemia vera.

Adult↗

Macrocytic anemia, thrombocytosis and nonlobulated megakaryocytes: the 5q-syndrome, a distinct entity.

The clinical, hematologic and histologic characteristics of six patients with refractory anemia with deletion of the long arm of chromosome No. 5 are described. These patients had a distinct hematologic picture with macrocytic anemia of mild to moderate severity, normal to low leukocyte count and increased platelet count. The long arm of chromosome No. 5 was deleted in the majority of bone marrow metaphases. The main cause of anemia was underproduction with decreased erythroid precursors in the bone marrow and no increase in peripheral blood reticulocytes. Two of five patients responded transiently to the administration of androgens. In vitro evaluation of the bone marrow growth pattern in semisolid agar culture system was performed in three patients and was found to be normal and distinct from that in patients with preleukemia. In a follow up of up to five years, no patient had changed hematologically and in none had leukemia developed. The 5q-syndrome is a distinct hematologic entity and probably more common than hitherto realized. This diagnosis may have therapeutic and prognostic implications.

Adult↗

Recovery of CFU-C after freezing of normal and leukemic human bone marrow.

Studies have been carried out to determine the viability of leukemic and normal human bone marrow, cryopreserved in liquid nitrogen at -196 degrees C, using changes in total cell numbers and granulocyte colony forming ability in vitro. These studies have shown that there is considerable variability in the recovery of CFU-C from individual specimens. When the overall recovery, in all patients, is taken into account, there is a gradual decline in CFU-C numbers to about 60% after 24 months of freezing. CFU-C recovery is closely correlated with recovery of total cell numbers.

Bone Marrow Cells↗

Autologous bone-marrow and peripheral blood buffy coat cell infusion in the treatment of chronic myeloid and acute leukemia.

Autologous marrow infusion has been attempted in three patients with chronic myeloid leukemia (two in blast crisis, one with severe myelofibrosis and pancytopenia) and one patient with acute lymphatic leukemia. One patient with blast crisis of CML expired prior to marrow infusion. One patient with myelofibrotic phase of CML is alive seven months post marrow infusion. The other two patients expired 6 and 16 days post marrow infusion. Bone-marrow repopulation is feasible in the face of severe myelofibrosis.

Adult↗