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M K Shah

Publications and source records attributed to M K Shah.

At least 19 recordsLinked to original sources
PubMed2001

Differential responses to ATPgammaS in the mesenteric and hindlimb vascular bed of the cat.

The mechanism by which the purinergic agonist adenosine 5'-O-(3 thiotriphosphate) (ATPgammaS) decreases vascular resistance was investigated in the mesenteric and hindlimb vascular beds of the cat. Injections of ATPgammaS into the hindlimb perfusion circuit elicited dose-dependent decreases in perfusion pressure while injections into the mesenteric circuit produced a biphasic response with an initial vasopressor response followed by a vasodepressor response. In the mesenteric vascular bed the pressor response to ATPgammaS was blocked by a P2X1 receptor antagonist. Also an inhibitor of nitric oxide synthase enhanced the vasoconstrictive responses to ATPgammaS. However, the vasodepressor response in the mesenteric bed was not altered by the adminstration of an alpha adrenergic receptor antagonist, a cyclooxygenase inhibitor, a P2Y1 receptor antagonist, or a K+ATP channel blocking agent. These data suggest that the vasopressor response to ATPgammaS in the mesenteric vascular bed of the cat is mediated via P2X1 receptor activation. The differential responses to ATPgammaS in the hindlimb and mesentery suggest differences in purinergic receptor distribution in the vascular system of the cat. In addition, the results suggest that prostaglandin synthesis, P2Y1 receptor activation, alpha receptor inhibition, and K+ATP channels activation play little to no role in mediating the vascular response to ATPgammaS in the mesentery of the cat.

Adamantane↗
PubMed2001

Mycobacterium haemophilum in immunocompromised patients.

Mycobacterium haemophilum, a recently described pathogen, can cause an array of symptoms in immunocompromised patients. To date, 90 patients with this infection have been described worldwide. We report our institution's experience with 23 patients who were treated from 1990 through 2000. Fourteen patients had undergone bone marrow transplantation, 5 were infected with human immunodeficiency virus, 3 had hematologic malignancies, and 1 had no known underlying immunosuppression. Clinical syndromes on presentation included skin lesions alone in 13 patients, arthritis or osteomyelitis in 4 patients, and lung disease in 6 patients. Although patients with skin or joint involvement had favorable outcomes, 5 of 7 patients with lung infection died. Prolonged courses of multidrug therapy are required for treatment. A diagnosis of M. haemophilum infection must be considered for any immunocompromised patient for whom acid-fast bacilli are identified in a cutaneous, synovial fluid or respiratory sample or for whom granulomas are identified in any pathological specimen.

Adult↗
PubMed2001

An in vitro resistance study of levofloxacin, ciprofloxacin, and ofloxacin using keratitis isolates of Staphylococcus aureus and Pseudomonas aeruginosa.

PURPOSE: We compared levofloxacin with ciprofloxacin and ofloxacin using the in vitro susceptibilities of Staphylococcus aureus (SA) and Pseudomonas aeruginosa (PA) keratitis isolates. DESIGN: Retrospective, clinical laboratory study of antibiotic susceptibility among keratitis isolates. PARTICIPANTS: Keratitis isolates from 200 patients with either SA or PA keratitis. METHODS: Minimum inhibitory concentrations (MICs) were determined for levofloxacin, ofloxacin, and ciprofloxacin for 93 SA keratitis isolates (68 fluoroquinolone-resistant and 25 susceptible, as determined by disk diffusion) and 107 PA keratitis isolates (13 fluoroquinolone-resistant and 94 susceptible). National Committee for Clinical Laboratory Standards susceptibilities were determined and analyzed statistically. Time kill studies were determined for fluoroquinolone-susceptible and -resistant isolates to all antibiotics at 8 microg/ml. The killing rates were determined by regression, and the colony count decreases were analyzed. MAIN OUTCOME MEASURES: The susceptibilities and potencies of levofloxacin, ciprofloxacin, and ofloxacin to SA and PA were determined from the MICs. Time kill studies determined the killing rates and decreases in colony counts. RESULTS: The fluoroquinolone-resistant SA susceptibilities to levofloxacin, ofloxacin, and ciprofloxacin were only 22%, 10%, and 3%, respectively. The fluoroquinolone-susceptible SA were 100% susceptible to all antibiotics, with levofloxacin demonstrating the best potency. The fluoroquinolone-resistant PA were resistant to all antibiotics. The fluoroquinolone-susceptible PA isolates were highly susceptible to levofloxacin, ofloxacin, and ciprofloxacin, with ciprofloxacin demonstrating the highest potency. For fluoroquinolone-susceptible SA and PA, the time kill studies determined that the killing rates and decreases in colony counts were equivalent for all three antibiotics tested. The time kill studies demonstrated no colony count decreases for the fluoroquinolone-resistant SA and PA. CONCLUSIONS: Taken together, our susceptibility and time kill data failed to demonstrate convincing differences in the susceptibility of SA and PA keratitis isolates to levofloxacin, ciprofloxacin, and ofloxacin. In general, bacterial isolates that were resistant to ciprofloxacin and ofloxacin were also resistant to levofloxacin.

Anti-Infective Agents↗
PubMed2001

Comparison of sevoflurane-nitrous oxide anaesthesia with the conventional intravenous-inhalational technique using bispectral index monitoring.

Ninety-one patients were randomly allocated to one of two groups. Group A was induced with a single vital capacity breath of 6% (end-tidal) sevoflurane in nitrous oxide-oxygen (2 : 1 l.min-1), whereas group B was induced with intravenous fentanyl 1 microg.kg-1 + propofol 2 mg.kg-1 followed by nitrous oxide-oxygen (2 : 1 l.min-1) and sevoflurane. Induction was considered to have been achieved when the bispectral index value decreased to below 70. Mean induction time in group A (95.2 s, 95% CI 88.5-101.9 s) was longer than group B (70.3 s, 95% CI 66.3-74.3 s; p < 0.0001). Mild coughing was more common in group A, but relative hypotension was more common in group B. There was no difference in the emergence times. Thirty minutes after emergence, there was no difference in the incidence of adverse effects, with the exception of essentially mild abdominal pain which was more frequent in group A.

Adult↗
PubMed2001

Vasodilator responses to ATP and UTP are cAMP dependent in the mesenteric vascular bed of the cat.

BACKGROUND: This study was designed to examine the responses to and the mechanism by which purinergic agonists decrease vascular resistance in the mesenteric vascular bed of the cat. METHODS AND RESULTS: Injections of ATP, UTP, and 2-MethylThioATP (2-MetSATP) into the mesenteric perfusion circuit elicited dose-dependent decreases in perfusion pressure while injections of beta,gamma-MethylATP (beta,gamma-MetATP) produced a biphasic response with an initial vasopressor response followed by a vasodilator response. The order of potency of the vasodilator response was 2-MetSATP > ATP > UTP > beta,gamma-MetATP. The vasodilator responses to ATP, UTP, 2-MetSATP, and beta,gamma-MetATP were increased in duration by the cAMP phosphodiesterase inhibitor, rolipram. However, vasodilator responses were not altered by the adminstration of a nitric oxide synthase inhibitor, a cGMP phosphodiesterase inhibitor, or a cyclooxygenase inhibitor. Treatment with PPADS, a P2X(1), P2Y(1), and P2Y(4) receptor antagonist, did not alter vasodilator responses to the purinergic agonists; however, the vasopressor component of the response to beta,gamma-MetATP was decreased. CONCLUSIONS: These data suggest that ATP, UTP, 2-MetSATP, and beta,gamma-MetATP dilate the mesentary vascular bed in the cat by a cAMP dependent mechanism, and that nitric oxide or prostaglandin release, cGMP accumulation, or activation of P2X(1), P2Y(1), or P2Y(4) receptors play little or no role in mediating vasodilator responses to the purinergic agonists in this regional vascular bed. In addition, these results suggest that the pressor component of the response to beta,gamma-MetATP is mediated by the activation of P2X(1) receptors.

Adenosine Triphosphate↗
PubMed2001

Empirical formulation of a generic query set for clinical information retrieval systems.

Information needs in clinical practice take the form of specific questions about a given clinical situation, and are best satisfied by concise and specific information retrieval. We sought to develop a comprehensive set of generic queries for information retrieval from electronic medical information resources. We collected one hundred and ten real-world questions asked at the point of care in a variety of settings, and from these developed a set of generic queries of which each of the real-world queries could be shown to be a special case. To provide allowed values for each of the concept terms in the queries, we defined generic nouns as unions of UMLS semantic types, and specified which of these were appropriate to each query. We have begun to use the set to index reference texts from general and subspecialty medicine, and found it capable of full text indexing in the clinical domain. We hypothesize that the query set can serve as a basis for more specialized query sets, and that it will remain generalizable to other electronic medical resources, indexing tasks, and non-UMLS controlled vocabularies.

Abstracting and Indexing↗
PubMed2000

The effect of the addition of ropivacaine or bupivacaine upon pruritus induced by intrathecal fentanyl in labour.

Sixty patients in early labour were randomly allocated to one of three groups. The control group received intrathecal fentanyl 25 microg, the ropivacaine group received intrathecal fentanyl 25 microg and ropivacaine 2.5 mg while the bupivacaine group received intrathecal fentanyl 25 microg and bupivacaine 2.5 mg. The incidence of pruritus was 100% in controls, compared with 85% in the ropivacaine group (not significant) and 75% in the bupivacaine group (p = 0.003). The severity of pruritus was significantly less in the ropivacaine (p = 0.006) and bupivacaine (p = 0.001) groups. Most patients developed pruritus by 30 min. Pruritus above the abdomen was not reduced in patients receiving local anaesthetics. There were no significant differences in the mean pain visual analogue score, systolic blood pressure, maternal heart rate and upper level of reduced pin-prick sensation in the first 30 min. Intrathecal ropivacaine and, more so, intrathecal bupivacaine reduce the incidence and severity of pruritus from intrathecal fentanyl for labour analgesia.

Adolescent↗
PubMed2000

A devastating ocular pathogen: beta-streptococcus Group G.

PURPOSE: To report the clinical findings, treatment, and outcomes of four cases of beta-streptococcus Group G (BHS-G) ocular infection. METHODS: The medical and microbiologic records of four cases of BHS-G ocular infection were retrospectively reviewed. RESULTS: Two cases of BHS-G endophthalmitis and two cases of BHS-G keratitis were recorded. Three patients developed fulminant infection within 12 hours of the onset of symptoms. One patient's history was incomplete. One patient developed endophthalmitis from a contaminated donor button; another following cataract surgery. One developed keratitis in a keratoplasty suture tract; and another patient developed a corneal abscess after being struck with a tree branch. The patient with the contaminated donor button developed overwhelming endophthalmitis resulting in no light perception vision, severe pain, and evisceration. The postoperative cataract patient developed a purulent endophthalmitis and is still hypotonus with light perception vision. The second keratitis patient developed a significant suture abscess with marked stromal loss but eventually healed. The traumatic keratitis patient developed a large ulcer with hypopyon and descemetocele but was lost to follow-up. CONCLUSIONS: This is the first report of a series of BHS-G ocular infections. The ocular infections were characterized by rapid onset, extreme inflammation, and--despite in vitro antibiotic sensitivity--a poor or sluggish response to antibiotic therapy.

Abscess↗
PubMed2000

New therapies for treating hypertension: what every physician should know.

Hypertension is a prevalent health problem and a major cause of morbidity and mortality in the United States. It is one of the most important modifiable risk factors for multiple medical problems including coronary artery disease, congestive heart failure, and end-stage renal disease. There are many efficacious antihypertension medications, each with its own indications and side effect profile. Furthermore, new drugs are being developed rapidly. This article features how to diagnose hypertension as well as describes pharmacological and nonpharmacological treatment options. The properties, proper use, and side effect profile of each of the nine classes of antihypertension drugs commonly used and three classes of medications on the horizon will be described. The purpose of this manuscript is to familiarize physicians with the antihypertension regimens commonly employed and to introduce drugs which may become available in the near future.

Adrenergic beta-Antagonists↗
PubMed1999

Human pulmonary dirofilariasis: review of the literature.

BACKGROUND: The dog heartworm Dirofilaria immitis is known to cause solitary pulmonary nodules in humans. Human pulmonary dirofilariasis (HPD) is more prevalent along the coastal regions of the United States, especially along the Mississippi River Valley. Diagnosis is generally made by surgical resection, since HPD is often preoperatively presumed to be lung cancer. METHODS: I searched for relevant clinical articles and case reports on HPD, using MEDLINE and the Index Medicus. I carefully reviewed each article for information regarding HPD. RESULTS: Of the 37 cases reviewed, 29 (78.4%) were in the southern and southeastern states. The youngest patient was a 33-year-old woman, and the oldest was a 79-year-old man (mean age, 57.3 years). This literature review found that 43.2% were symptomatic, 51.4% were asymptomatic, and 5.4% were not recorded. Solitary lesions were found in 89.7%, with a mean diameter of 1.9 cm. CONCLUSION: Based on the available literature and epidemiologic data, HPD should be considered in the differential diagnosis of pulmonary nodules in the appropriate clinical and geographic setting.

Dirofilariasis↗
PubMed1999

Comparison of internal medicine, pediatric, and medicine/pediatrics applicants and factors influencing career choices.

BACKGROUND: A reemergence of medical students choosing primary care is occurring, with medicine/pediatrics as an increasingly popular option. We compared applicants to pediatrics, medicine, and medicine/pediatrics and the factors that influence career choice. METHODS: We designed a survey to gather objective data and information shown to influence career choices. Applicants interviewing in our three primary care programs completed the survey. RESULTS: Pediatric applicants were more likely to be women and to choose their career in the 2nd year of medical school. Medicine/Pediatrics applicants had the highest interest in practicing primary care and in pursuing an academic career. However, they had the smallest number of role models. The average education debt was the same. CONCLUSION: Differences in applicants applying to primary care programs may be used to target particular applicants and to counsel medical students on career choice.

Adult↗
PubMed1998

A unique case of Cryptococcus laurentii keratitis spread by a rigid gas permeable contact lens in a patient with onychomycosis.

PURPOSE: We report the first case of fungal keratitis caused by Cryptococcus laurentii, a nonneoformans species. METHODS: A case of C. laurentii keratitis in a diabetic, gas permeable contact lens wearer was diagnosed after microbiologic evaluation of the corneal button after emergent keratoplasty. The excised cornea was also culture positive for Staphylococcus aureus and Fusarium solani. The medical history was significant for onychomycosis of the right great toe 2 months previously. Cultures of the toenail and of the contact lens case were also positive for C. laurentii and F. solani. RESULTS: An initial penetrating keratoplasty with histopathologically clear margins was unsuccessful in preventing intraocular spread of the fungal infection. Despite a repeat limbus-to-limbus therapeutic keratoplasty, pars plana vitrectomy, multiple anterior chamber washouts, intravitreal antifungal injections, and systemic antifungal treatment, the eye was ultimately lost due to ongoing inflammation, ocular hypotony, and a total retinal detachment. Histopathologic examination of the enucleated eye demonstrated filamentous fungi but no yeast forms. CONCLUSIONS: C. laurentii, a nonneoformans species, should be included in the differential diagnosis of fungal keratitis. This unique case also demonstrates the importance of a thorough clinical history and proper contact lens hygiene, particularly in a diabetic patient.

Antifungal Agents↗
PubMed1998

Treatment of symptomatic chronic adenotonsillar hypertrophy with amoxicillin/clavulanate potassium: short- and long-term results.

OBJECTIVE: To evaluate the short- and long-term effects of treatment of symptomatic chronic adenotonsillar hypertrophy (CATH) with a 30-day course of amoxicillin/clavulanate potassium (AMOX/CLAV). PATIENTS: Children 2 to 16 years of age with obstructive symptoms attributable to CATH, who did not have a history of recurrent adenotonsillitis. DESIGN: A prospective, randomized, double-blinded, placebo-controlled trial. SETTING: Ambulatory clinic of a tertiary care hospital. INTERVENTION: Patients were randomly treated with 30-day courses of either placebo (PLAC) or AMOX/CLAV (40 mg/kg in 3 divided doses daily). OUTCOME MEASURES: Patients' signs and symptoms were assessed by physical examination and by both physician and parental forced-choice questionnaires 1, 3, and 24 months after treatment. The decision to proceed to surgery or to continue expectant management was made for all patients by the same physician, based on reported symptoms and physical findings. RESULTS: Treatment with a 30-day course of AMOX/CLAV significantly reduced the need for surgery in the short term compared with PLAC (37.5% vs 62.7%) at 1-month follow-up). The reduced need for surgery in the AMOX/CLAV-treated group persisted at 3 months (AMOX/CLAV 54.5% vs PLAC 85.7%) and 24 months (AMOX/CLAV 83.3% vs PLAC 98.0%). CONCLUSIONS: A 30-day course of AMOX/CLAV significantly reduces the need for surgery in children with obstructive adenotonsillar hypertrophy at 1-month follow-up. This relative reduction persists at 3 and 24 months posttreatment, although the absolute percentages of patients requiring surgery increased in both groups as time after treatment increased. The reduction in symptoms in AMOX/CLAV-treated patients is modest but significant even in long-term follow-up. The precise role of this treatment for CATH is yet to be determined; however, our results suggest that a 30-day course of AMOX/CLAV can be used in situations when a temporary relief in symptoms is desirable or surgery would incur unacceptable risk.

Adenoids↗
PubMed1997

Comparison of responses to rat and human adrenomedullin in the hindlimb vascular bed of the cat.

Responses to rat (r) adrenomedullin (ADM) and human (h) ADM were compared in the hindlimb vascular bed of the cat under conditions of controlled blood flow. Intra-arterial injections of rADM and hADM in doses of 0.03-1 nmol caused dose-related decreases in hindlimb perfusion pressure. In terms of relative vasodilator activity, rADM was similar to hADM. The time course of the vasodilator response and the recovery half times (T1/2) for the vasodilator response to rADM and hADM were not significantly different. Decreases in hindlimb perfusion pressure in response to rADM and hADM were not altered by the calcitonin gene-related peptide receptor antagonist, rCGRP(8-37), at the same time, vasodilator responses to calcitonin gene-related peptide (CGRP) were significantly reduced. The T1/2 of the vasodilator response to rADM and hADM were significantly greater after administration of the cAMP-selective, type IV phosphodiesterase inhibitor, rolipram. These data demonstrate that decreases in hindlimb perfusion pressure in response to rADM and hADM are similar and that vasodilator responses to rADM are not dependent on the activation of CGRP receptors in the hindlimb vascular bed of the cat. These data further suggest that decreases in hindlimb perfusion pressure in response to rADM are mediated by smooth muscle increases in cAMP levels.

Adrenomedullin↗
PubMed1997

A case of tracheal obstruction during oesophageal removal of a foreign body.

A patient was admitted with an impacted foreign body in the oesophagus. Repeated attempts to remove it during oesophagoscopy proved difficult and caused obstruction of the trachea during manipulation of the foreign body. A smaller endotracheal tube was subsequently placed in the trachea relieving the obstruction.

Esophagoscopes↗
PubMed1997

Acute pain service, Kandang Kerbau Hospital, 1995--a first year's experience.

AIM: To determine the efficacy and safety of the different modes of post-operative analgesia in the first 24 hours for both caesarean section and major gynaecological procedures. METHODS: Being a purely descriptive study, the patients were not randomised to the post-operative analgesic mode. The choice was made both by the patient and the anaesthetist. The modes employed were continuous intravenous morphine, continuous intravenous pethidine, epidural morphine/bupivacaine, epidural bupivacaine/fentanyl and spinal morphine. During the first 24 hours, the patients' maximum pain scores, ability to sleep well, presence of nausea and/or vomiting, pruritus, respiratory depression and drowsiness and/or giddiness were elicited. Backache and inflammation at the site of insertion of the epidural catheter were also elicited in patients on regional analgesia. They were also asked if they were satisfied with the Pain Service. RESULTS: Out of 2,024 patients, 60% had undergone caesarean section and 40% had undergone major gynaecological procedures. Continuous intravenous morphine, the most common mode, was used in 83% of obstetric patients and 47.9% of gynaecological patients. Only one obstetric patients and one gynaecological patient complained of severe pain at rest while 12 obstetric patients and 3 gynaecological patients had severe pain on movement or coughing. Side-effects, most commonly nausea and/or vomiting and drowsiness and/or giddiness, were present in 8.8% of obstetric patients and 32.5% of gynaecological patients. 99.3% of obstetric patients and 99.6% of gynaecological patients were overall satisfied with their analgesia. CONCLUSION: Our post-operative analgesic modes were found to be effective and safe.

Analgesia↗