PubMed Health⌕ Search

Biomedical subjects

Mohammad Khan

Publications and source records attributed to Mohammad Khan.

8 recordsLinked to original sources
PubMed2006

Pneumonia in mice inoculated experimentally with Acanthamoeba polyphaga mimivirus.

In an attempt to elucidate whether Acanthamoeba polyphaga mimivirus (APM) was pathogenic (i.e., induces histological evidence of inflammation or tissue destruction or both) in mammalian host, we inoculated adult BALB/c (n=6) and C57BL/6 (n=6) mice with APM via intracardiac route. C57BL/6 mice developed histopathological features of pneumonia by post-inoculation day (PID) 3 and BALB/c mice, by PID7. The histopathological features of pneumonia, characterized by the presence of thickened alveolar walls with cellular infiltrates comprising mononuclear leukocytes, macrophages and lymphocytes, diffuse alveolar damages with the formation of hyaline membrane and erythrocytes in the alveolar lumen, were most marked by PID 7. We conclude that APM is pathogenic in mice in experimental conditions.

Acanthamoeba↗
PubMed2005

Gastroschisis revisited: role of intraoperative measurement of abdominal pressure.

BACKGROUND: Animal studies have shown that visceral circulation is well preserved when intraabdominal pressure does not exceed 20 mm Hg. Our aim was to analyze the outcomes of a series of infants with gastroschisis whose surgical management was directed by the intraoperative measurement of bladder pressure. METHODS: Forty-two neonates with gastroschisis were surgically managed using intraoperative measurement of bladder pressure at a tertiary care center between July 31, 1992, and March 20, 2004, and their outcome was evaluated. Primary closure with or without prosthetic material was performed when pressures measured 20 mm Hg or less. Delayed closure using a silon pouch was performed when pressures measured more than 20 mm Hg. Categorical variables were analyzed including mode of delivery, associated anomalies, type of closure, complications, and mortality. Continuous variables were analyzed including gestational age, birth weight, bladder pressure, time to full feeds, and length of hospital stay. Categorical and continuous variables for both groups were compared using Fisher's Exact and Wilcoxon's rank-sum tests, respectively, and a significance level of .05 was used. Preapproval of this study was obtained from the Institutional Review Board (No. 6690). RESULTS: Thirty-three (79%) neonates with a mean bladder pressure of 16 mm Hg underwent primary closure and 9 neonates with a mean bladder pressure of 27 mm Hg underwent delayed closure with a silon pouch that was not spring loaded ( P < .03). Patients treated with primary closure had faster return to full feeds and significantly shorter hospital length of stay compared with patients treated by delayed closure ( P = .04). Surgical morbidity and mortality was nil in patients after primary closure. One patient with total abdominal evisceration died during attempted delayed closure and another patient required reoperation for bowel necrosis after delayed closure. CONCLUSION: Primary closure was safely accomplished in 100% of neonates with gastroschisis whose bladder pressure measured 20 mm Hg or less. Further, this group of patients had a faster return to full feeds and a significantly shorter hospital length of stay compared with neonates who required delayed closure.

Abnormalities, Multiple↗
PubMed2005

Long-term survival of high-risk pediatric patients with primitive neuroectodermal tumors treated with antineoplastons A10 and AS2-1.

Primitive neuroectodermal tumors (PNETs) are usually successfully treated with craniospinal radiation and chemotherapy; however, difficulties with standard treatment can be encountered in very young children, in adult patients at high risk of complication from standard treatment, and in patients with recurrent tumors. Thirteen children, either with recurrent disease or high risk, were treated in phase II studies with antineoplastons (ANP). The median age of patients was 5 years, 7 months (range, 1-11). Medulloblastoma was diagnosed in 8 patients, pineoblastoma in 3 patients, and other PNET in 2 patients. Previous treatments included surgery in 12 patients (1 had biopsy only, suboccipital craniotomy), chemotherapy in 6 patients, and radiation therapy in 6 patients. Six patients had not received prior chemotherapy or radiation. The treatment consisted of intravenous infusions of 2 formulations of ANP, A10 and AS2-1, and was administered for an average of 20 months. The average dosage of A10 was 10.3 g/kg/d and of AS2-1 was 0.38 g/kg/d. Complete response was accomplished in 23%, partial response in 8%, stable disease in 31%, and progressive disease in 38% of cases. Six patients (46%) survived more than 5 years from initiation of ANP; 5 were not treated earlier with radiation therapy or chemotherapy. The serious side effects included single occurrences of fever, granulocytopenia, and anemia. The study is ongoing and accruing additional patients. The percentage of patients' response is lower than for standard treatment of favorable PNET, but long-term survival in poor-risk cases and reduced toxicity makes ANP promising for very young children, patients at high risk of complication of standard therapy, and patients with recurrent tumors.

Antineoplastic Agents↗
PubMed2004

Long-term survival and complete response of a patient with recurrent diffuse intrinsic brain stem glioblastoma multiforme.

Recurrent diffuse intrinsic brain stem glioblastoma multiforme carries an extremely poor prognosis and a median survival of less than 7 months. In this article, the authors report good results in a 40-year-old man diagnosed with glioblastoma multiforme who received antineoplastons. The patient's brain tumor was diagnosed in May 1999, and he subsequently underwent subtotal tumor resection and standard radiation therapy. Magnetic resonance imaging and positron emission tomography scans documented his tumor recurrence. Approximately 2 months after completion of radiation therapy, he was admitted for administration of intravenous antineoplastons A10 and AS2-1 through a subclavian venous catheter by intermittent bolus injections 6 times per day using a portable pump. Administration of antineoplastons A10 and AS2-1 was over 655 consecutive days with the exception of a few short interruptions. The maximum dosage of A10 was 8.15 g/kg/d and AS2-1 0.35 g/kg/d. Antineoplastons A10 and AS2-1 administration was very well tolerated with only mild reversible side effects. Follow-up magnetic resonance imaging and positron emission tomography scans revealed decrease and eventually disappearance of the tumor. A complete response was documented after approximately 1 year of antineoplastons A10 and AS2-1 administration. More than 4 years later, off antineoplastons A10 and AS2-1, the patient is tumor free, able to carry on normal activities, and works full-time, and his Karnofsky Performance Status increased from 50 to 100. Extensive phase II trials with antineoplastons A10 and AS2-1 in patients with glioblastoma multiforme are nearing completion. These trials may provide more data regarding the efficacy of antineoplastons A10 and AS2-1 in the treatment of glioblastoma multiforme in untreated patients compared to the results in those patients with tumor recurrence after radiation therapy.

Adult↗
PubMed2003

Does competitive flow reduce internal thoracic artery graft patency?

BACKGROUND: In coronary arteries with moderate stenosis, competitive flow may lead to internal thoracic artery (ITA) graft occlusion. The goals of this study were to determine if competitive flow reduces ITA patency, and if there is a degree of coronary stenosis below which ITAs should not be used. METHODS: From 1972 to 1999, 50,278 patients underwent primary coronary artery bypass grafting (CABG). Of these, 2,002 had at least one ITA graft and postoperative angiography before coronary reintervention; 2,999 angiograms of 2,121 ITAs were made. Time-related ITA occlusion was modeled using longitudinal analysis to identify its risk factors while accounting for lack of independence introduced by repeated angiography and multiple ITA anastomoses per patient. Proximal coronary stenosis (maximum preoperative stenosis between ITA anastomosis and aorta) was the surrogate for competitive flow. RESULTS: Unadjusted ITA patency was 93%, 89%, 90%, and 92% at 1, 5, 10, and 15 years after CABG. Risk factors associated with ITA occlusion were lesser degree of proximal coronary stenosis (p < 0.0001); longer time from CABG in grafts to non-left anterior descending coronary arteries (p < 0.0001); female sex (p = 0.0003); later date of CABG (p = 0.01); right ITA (p < 0.0001); and smoking (p < 0.0001). In all arteries, as preoperative proximal coronary stenosis decreased, ITA patency declined; however, at no degree of stenosis was there a sharp decline. CONCLUSIONS: Internal thoracic artery patency decreases as coronary competitive flow increases. However, the nature of this relationship indicates ITAs should not be abandoned at moderate grades of stenosis.

Aged↗
PubMed2003

Serum cytokine profiles in patients with Plasmodium vivax malaria: a comparison between those who presented with and without hyperpyrexia.

Serum cytokine profiles in patients with Plasmodium vivax malaria who presented with and without hyperpyrexia were compared by a retrospective review of the medical records of the consecutive patients seen at the military hospitals near the demilitarized zone in the Republic of Korea from April 2000 through October 2001. Of 162 male patients studied, 120 (86.4%) presented with hyperpyrexia (i.e., an axillary temperature > or = 40 degrees C). The mean +/- SEM ages of the patients with and without hyperpyrexia were 21.5 +/- 0.14 and 21.9 +/- 0.39 years, respectively (P = 0.33). The mean +/- SEM concentrations of serum interleukin (IL)-6 (379.7 +/- 44.1 pg/mL versus 105.4 +/- 26.8 pg/mL; P = 0.002), IL-10 (583.4 +/- 58.2 pg/mL versus 142.4 +/- 39.7 pg/mL; P = 0.0001), and interferon-gamma (312.6 +/- 33.9 pg/mL versus 112.9 +/- 27.1 pg/mL; P = 0.0001) were significantly higher in patients with hyperpyrexia compared with those without hyperpyrexia. The mean +/- SEM concentrations of serum tumor necrosis factor-alpha were 155.5 +/- 54.5 pg/mL and 109.9 +/- 29.3 pg/mL (P = 0.27) in patients who presented with and without hyperpyrexia, respectively. Further studies are needed to examine whether serum concentrations of these cytokines also parallel their concentrations at the tissue sites of their production and action.

Adult↗
PubMed2002

Characterization of Salmonella enterica derivatives harboring defined aroC and Salmonella pathogenicity island 2 type III secretion system (ssaV) mutations by immunization of healthy volunteers.

The attenuation and immunogenicity of two novel Salmonella vaccine strains, Salmonella enterica serovar Typhi (Ty2 Delta aroC Delta ssaV, designated ZH9) and S. enterica serovar Typhimurium (TML Delta aroC Delta ssaV, designated WT05), were evaluated after their oral administration to volunteers as single escalating doses of 10(7), 10(8), or 10(9) CFU. ZH9 was well tolerated, not detected in blood, nor persistently excreted in stool. Six of nine volunteers elicited anti-serovar Typhi lipopolysaccharide (LPS) immunoglobulin A (IgA) antibody-secreting cell (ASC) responses, with three of three vaccinees receiving 10(8) and two of three receiving 10(9) CFU which elicited high-titer LPS-specific serum IgG. WT05 was also well tolerated with no diarrhea, although the administration of 10(8) and 10(9) CFU resulted in shedding in stools for up to 23 days. Only volunteers immunized with 10(9) CFU of WT05 mounted detectable serovar Typhimurium LPS-specific ASC responses and serum antibody responses were variable. These data indicate that mutations in type III secretion systems may provide a route to the development of live vaccines in humans and highlight significant differences in the potential use of serovars Typhimurium and Typhi.

Bacterial Proteins↗