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H Hashimi

Publications and source records attributed to H Hashimi.

14 recordsLinked to original sources
PubMed1995

Programmed cell death in the Drosophila central nervous system midline.

BACKGROUND: During the development of the central nervous system, large numbers of cells die by programmed cell death. This process requires the activity of specific gene products and subserves functions that include regulating the sizes of interacting cell populations and removing cells that provide transient functions. Resolution of programmed cell death often involves the elimination of dying cell corpses by phagocytic macrophages. In Drosophila, the reaper gene plays a crucial role in mediating programmed cell death; chromosomal deficiencies which remove reaper result in an absence of programmed cell death. We have used a reaper-deficiency mutant strain Df(3R)H99 (or H99), in conjunction with strains containing cell-type-specific markers, to examine the role of programmed cell death in differentiation of the embryonic central nervous system midline. RESULTS: Midline cell death was identified both by the presence of excess midline cells in H99 mutants and by the engulfment of dying midline cells by macrophages in wild-type embryos. These developmental deaths are lineage-specific: prominent midline glial death was observed, while little if any death was detected among the ventral unpaired median neurons. Examination of H99 mutants indicates that cell death is not required for the formation of macrophage precursors, or for their subsequent migration throughout the embryo; however, in the absence of dying cells, macrophage precursors do not exhibit morphological differentiation or phagocytosis. In both wild-type and H99 mutant embryos, a subset of macrophages migrate along the ventral midline. This midline migration is not observed in single-minded mutants, in which ventral midline cells fail to develop. CONCLUSIONS: Programmed cell death plays a crucial role in the development of the central nervous system midline, and dying midline cells are rapidly eliminated by phagocytic macrophages. It seems that the generation of engulfment signals in cells undergoing programmed cell death is downstream of reaper gene function, and that central nervous system midline and/or ventral epidermal cells provide directional cues for migrating macrophages.

Animals↗
PubMed1991

Continuous intercostal nerve block for postoperative analgesia after surgical treatment of the upper part of the abdomen.

Continuous intercostal nerve block can be used effectively for pain relief after abdominal operations. We have developed a greatly simplified technique instituted by the surgeon at operation using bupivacaine hydrochloride (Marcain, ASTRA). Our method proved to be effective in providing postoperative analgesia in 93.4 per cent of the patients undergoing cholecystectomy through a transverse abdominal incision. No additional analgesia was required in the first four days postoperatively while the system was in use. In addition, no postoperative pulmonary complications or adverse reactions to bupivacaine hydrochloride or the procedure were encountered. This method proved to be a success in postoperative pain relief and we highly recommend that it be used routinely.

Adult↗
PubMed1989

Second look operation in managing carcinoma of the pancreas and periampullary region.

From a total of 153 patients with carcinoma of the periampullary region and of the head of the pancreas, 127 underwent surgical treatment. There were 79 men and 48 women with a mean age of 65 years (a range of 39 to 90 years). Of these, 26 had resectional operations. Fifteen were carried out at the initial laparotomy and 11 at a second look operation (SLO). Of the 112 patients who had a palliative bypass at the initial laparotomy, 30, who were less than 65 years of age and were fit and remained so when assessed at six and 12 weeks postoperatively, were re-evaluated for SLO. Of these, 12 had evidence of metastases and, therefore, were not considered for SLO. Eleven had a successful resection, and in seven, attempted resection had to be abandoned because of local invasion. The five year survival rate was 50 per cent for carcinoma of the periampullary region and 9 per cent for carcinoma of the head of the pancreas after primary resection. The comparable rates after SLO were 33.3 and 12.5 per cent, respectively. Based on our experience, SLO should be considered in young, fit patients as associated pancreatitis can make some tumors seem locally invasive and, hence, appear unresectable at the initial laparotomy.

Adult↗
PubMed1988

Continuous intercostal nerve block for pain relief after thoracotomy.

Others have demonstrated the effectiveness of intercostal analgesia with bupivacaine hydrochloride (Marcain Plain; Astra). We present a greatly simplified method of effecting this. Our method is dependent on an intact pleura. To date, we have utilized this technique in 81 patients. Seventy-five (92.6%) required no additional analgesic in the first 24 hours following operation and 66 (81.5%), in the subsequent four days. Only 2 patients had postoperative pulmonary complications. No complication related either to the procedure or to the infusion of bupivacaine occurred. The technique as described here is a safe and reliable method of providing analgesia without any side effects after thoracotomy.

Adult↗
PubMed1981

Interrelationships between regional left ventricular function, coronary blood flow, and myocellular necrosis during the initial 24 hours and 1 week after experimental coronary occlusion in awake, unsedated dogs.

This study examined the relationships between the left ventricular (LV) regional function, regional myocardial blood flow (RMBF), and myocellular necrosis after sudden proximal occlusion of the left anterior descending coronary artery (LAD) in 36 awake, unsedated dogs. Net wall thickening during systole (NET) was used to assess regional LV function, was expressed as percent control, and was measured with chronically implanted ultrasonic crystals. RMBF was measured with 8- to 10-micrometer radioactive microspheres. In regions with a moderate degree of functional loss, NET fell to 35.3 +/- 2.2% of control at 5 minutes when RMBF fell from 1.9 +/- 0.08 to .086 +/- 0.09 ml/g per min (P less than 0.05). No significant change occurred in midwall or epicardial RMBF. The relationship between endocardial flow and NET was non-linear (r = 0.69, P less than 0.0001). In these segments, subsequent changes in RMBF were unrelated to corresponding functional alterations through 24 hours. In segments with paradoxic systolic wall thinning RMBF fell in endocardial, midwall, and epicardial layers; endocardial ischemia was most severe (0.30 +/- 0.05 ml/g per min). Segmental myocellular necrosis was most severe in the endocardial layer and correlated significantly with both RMBF and segmental function. Myocellular necrosis increased in severity as flow was reduced below 70-75% of normal. Thus, in this model of LV ischemia, (1) regional LV functional loss is most sensitive to reductions in endocardial RMBF; (2) subsequent increases in RMBF are largely unassociated with functional recovery; (3) transmural ischemia results in paradoxical systolic wall thinning.

Animals↗
PubMedDate not supplied

Pancreatic carcinoma. Second-look operation?

From a total of 146 patients with carcinoma of the head of the pancreas and preiampullary region, treated surgically, 31 underwent Whipple's pancreaticoduodenectomy. Eighteen were carried out at the initial laparotomy and thirteen at a second-look operation (SLO). Of the 128 patients who underwent bypass as palliative procedure, 36 were selected. All were less than 65 yr of age, and their general condition continued to improve postoperatively. They were reassessed regularly with view to SLO. Whipple's procedure was accomplished in 13 cases. Ten out of 13 patients had a raised serum amylase at the initial exploration, indicating coexisting pancreatitis. SLO should be considered in fit patients with evidence of concomitant acute pancreatitis at the initial laparotomy, since pancreatitis can make some tumors seem locally invasive and hence unresectable at the initial laparotomy.

Adult↗